Tumgik
#dataframe indexing
codewithnazam · 6 months
Text
DataFrame in Pandas: Guide to Creating Awesome DataFrames
Explore how to create a dataframe in Pandas, including data input methods, customization options, and practical examples.
Data analysis used to be a daunting task, reserved for statisticians and mathematicians. But with the rise of powerful tools like Python and its fantastic library, Pandas, anyone can become a data whiz! Pandas, in particular, shines with its DataFrames, these nifty tables that organize and manipulate data like magic. But where do you start? Fear not, fellow data enthusiast, for this guide will…
Tumblr media
View On WordPress
0 notes
nellectronic · 1 year
Text
tagged by @airshipvalentine!! 💖💖
relationship status: eternally single
favorite color: green! specifically dark green
song stuck in my head: mermaids by florence + the machine
last song i listened to: morungens liebeslied by qntal
3 favorite foods: bread, chocolate chip cookies, ice cream. yes i know it’s an extremely boring answer but they’re classics
last thing i googled: Unhandled error: DataFrame index must be unique for orient=‘index’
dream trip: i am very much a stay-in-bed-all-the-time type of person so idk if i would ever want to travel just for fun… but i would love to visit old friends i haven’t talked to in forever and/or internet friends i’ve never actually met in person and just like, hang out for a while
what i want right now: a nap. an explanation for my dataframe index problem that is even remotely comprehensible to me. to be able to wear shorts/dresses to work (the joys of working with chemicals). friends. the motivation to actually initiate conversation with my friends. the motivation to work on literally any of my fics. ideas for creative projects i’m actually excited about. longer hair. music recs. a hug. i could go on but i think that’s enough for now
if you’re reading this, you’ve been tagged!
2 notes · View notes
maddiem4 · 2 years
Text
If you want to go legitimately fucking insane try to set up a pandas DataFrame with a MultiIndex and then efficiently filter rows by one of those index columns matching a bitwise filter.
Seems like it should be easy. Seems like it should be efficient. Sure is easy and fast if you give up on using a fancy index and just filter on a column. But as soon as it's an index you are somehow unimaginably fucked. None of the filtering by criteria tools work against indexes. You will, however, spend hours thinking "oh, but here's a clue!"
It is an extraordinary level of effort to achieve "discard non-matching rows and smoosh the rest together."
2 notes · View notes
intelarti · 14 days
Text
K-Means Clustering Project
from pandas import Series, DataFrame import pandas as pd import numpy as np import os import matplotlib.pylab as plt from sklearn.model_selection import train_test_split from sklearn import preprocessing from sklearn.cluster import KMeans
standardize predictors to have mean=0 and sd=1
predictors=predvar.copy()
from sklearn import preprocessing predictors.loc[:,'CODPERING']=preprocessing.scale(predictors['CODPERING'].astype('float64')) predictors.loc[:,'CODPRIPER']=preprocessing.scale(predictors['CODPRIPER'].astype('float64')) predictors.loc[:,'CODULTPER']=preprocessing.scale(predictors['CODULTPER'].astype('float64')) predictors.loc[:,'CICREL']=preprocessing.scale(predictors['CICREL'].astype('float64')) predictors.loc[:,'CRDKAPRACU']=preprocessing.scale(predictors['CRDKAPRACU'].astype('float64')) predictors.loc[:,'PPKAPRACU']=preprocessing.scale(predictors['PPKAPRACU'].astype('float64')) predictors.loc[:,'CODPER5']=preprocessing.scale(predictors['CODPER5'].astype('float64')) predictors.loc[:,'RN']=preprocessing.scale(predictors['RN'].astype('float64')) predictors.loc[:,'MODALIDADC']=preprocessing.scale(predictors['MODALIDADC'].astype('float64')) predictors.loc[:,'SEXOC']=preprocessing.scale(predictors['SEXOC'].astype('float64'))
k-means cluster analysis for 1-9 clusters
from scipy.spatial.distance import cdist clusters=range(1,10) meandist=[]
for k in clusters: model=KMeans(n_clusters=k) model.fit(pred_train) clusassign=model.predict(pred_train) meandist.append(sum(np.min(cdist(pred_train, model.cluster_centers_, 'euclidean'), axis=1)) / pred_train.shape[0])
"""
Plot average distance from observations from the cluster centroid
to use the Elbow Method to identify number of clusters to choose
"""
plt.plot(clusters, meandist)
plt.xlabel('Number of clusters')
plt.ylabel('Average distance')
plt.title('Selecting k with the Elbow Method')
Tumblr media
# Interpret 3 cluster solution
model3=KMeans(n_clusters=4)
model3.fit(pred_train)
clusassign=model3.predict(pred_train)
# plot clusters
from sklearn.decomposition import PCA
pca_2 = PCA(2)
plot_columns = pca_2.fit_transform(pred_train)
plt.scatter(x=plot_columns[:,0], y=plot_columns[:,1], c=model3.labels_,)
plt.xlabel('Canonical variable 1')
plt.ylabel('Canonical variable 2')
plt.title('Scatterplot of Canonical Variables for 4 Clusters')
plt.show()
Tumblr media
FINALLY calculate clustering variable means by cluster
clustergrp = merged_train.groupby('cluster').mean() print ("Clustering variable means by cluster") print(clustergrp)
Clustering variable means by cluster level_0 index CODPERING CODPRIPER CODULTPER CICREL \ cluster 0 4783.973187 2202.005156 0.963712 0.969521 1.470092 0.147501 1 4749.533996 9139.503897 -0.918675 -0.914307 -0.614964 0.224046 2 4725.493210 11053.778395 -0.714950 -0.747535 -0.497807 -0.977341 3 4783.481132 5087.423742 1.344160 1.367493 -0.942482 0.198045 CRDKAPRACU PPKAPRACU CODPER5 RN MODALIDADC SEXOC cluster 0 -0.033407 -0.327742 -1.293936 -0.012300 0.423588 -0.123853 1 0.579928 0.318376 0.670651 -0.022002 -0.456030 0.030189 2 -1.575391 -0.104314 0.907238 0.032409 -0.104038 0.146536 3 0.376772 -0.039336 -0.150108 0.000886 0.460660 -0.047461
Detailed Breakdown:
Clusters: The data is divided into four clusters (0, 1, 2, 3), number that was defined using the Elbow method.
Variables: Various clustering variables are listed such as CODPERING, CODPRIPER, CODULTPER, etc.
For each cluster:
Cluster 0:
The mean of CODPERING is 2202.005156.
The mean of CODPRIPER is 0.963712.
Other variables have their respective means listed.
Cluster 1:
The mean of CODPERING is 9139.503897.
The mean of CODPRIPER is -0.918675.
Other variables have their respective means listed.
Cluster 2:
The mean of CODPERING is 11053.778395.
The mean of CODPRIPER is -0.714950.
Other variables have their respective means listed.
Cluster 3:
The mean of CODPERING is 5087.423742.
The mean of CODPRIPER is 1.344160.
Other variables have their respective means listed.
Summary:
There is the calculates and prints the mean values of different clustering variables for each cluster. This output helps to understand the characteristics of each cluster based on the mean values of the variables, which can be useful for further analysis and interpretation of the clustering results
0 notes
ggype123 · 17 days
Text
Lasso Regression Analysis for Predicting School Connectedness
Introduction
A lasso regression analysis was performed to identify the most important predictors of school connectedness among adolescents. The lasso regression technique is effective for variable selection and shrinkage, which helps in interpreting models by selecting only the most relevant variables and shrinking the coefficients of less important ones towards zero.
Methodology
The following 23 predictors were evaluated in the analysis:
Demographics: Age, Gender, Ethnicity (Hispanic, White, Black, Native American, Asian)
Substance Use: Alcohol use, Marijuana use, Cocaine use, Inhalant use
Family and Social Factors: Availability of cigarettes at home, Parental public assistance, School expulsion history
Behavioral and Psychological Factors: Alcohol problems, Deviance, Violence, Depression, Self-esteem
Family and School Connectedness: Parental presence, Parental activities, Family connectedness, GPA
The response variable was school connectedness, a quantitative measure. All predictor variables were standardized to have a mean of zero and a standard deviation of one to ensure comparability of coefficients.
Data were randomly divided into a training set (70% of the observations, N=3201N = 3201N=3201) and a test set (30% of the observations, N=1701N = 1701N=1701). The lasso regression model was estimated using 10-fold cross-validation on the training set to select the best subset of predictors, and the model was validated using the test set. The cross-validation mean squared error (MSE) was used to determine the optimal model.
Results
Figure 1. Change in the Validation Mean Squared Error at Each Step
Of the 23 predictors, 18 were retained in the final model. The variables most strongly associated with school connectedness included:
Self-Esteem: Positively associated with school connectedness.
Depression: Negatively associated with school connectedness.
Violence: Negatively associated with school connectedness.
GPA: Positively associated with school connectedness.
Other significant predictors included:
Positive Associations: Older age, Hispanic and Asian ethnicity, Family connectedness, Parental activities.
Negative Associations: Male gender, Black and Native American ethnicity, Alcohol use, Marijuana use, Cocaine use, Availability of cigarettes at home, Deviant behavior, History of school expulsion.
These 18 variables accounted for 33.4% of the variance in the school connectedness response variable.
Syntax and Output
Below is the Python code used to perform the lasso regression and the resulting output:
python
Copy code
# Import necessary libraries from sklearn.linear_model import LassoCV from sklearn.model_selection import train_test_split from sklearn.preprocessing import StandardScaler import pandas as pd import numpy as np import matplotlib.pyplot as plt # Load the data # Assume data is in a DataFrame 'df' X = df[['age', 'gender', 'hispanic', 'white', 'black', 'native_american', 'asian', 'alcohol_use', 'marijuana_use', 'cocaine_use', 'inhalant_use', 'cigarettes_in_home', 'parent_public_assistance', 'school_expulsion', 'alcohol_problems', 'deviance', 'violence', 'depression', 'self_esteem', 'parental_presence', 'parental_activities', 'family_connectedness', 'gpa']] y = df['school_connectedness'] # Standardize the data scaler = StandardScaler() X_scaled = scaler.fit_transform(X) # Split the data X_train, X_test, y_train, y_test = train_test_split(X_scaled, y, test_size=0.3, random_state=42) # Perform lasso regression with cross-validation lasso = LassoCV(cv=10, random_state=42).fit(X_train, y_train) # Display the coefficients coef = pd.Series(lasso.coef_, index=X.columns) print("Lasso Regression Coefficients:") print(coef[coef != 0].sort_values()) # Plot change in MSE plt.figure(figsize=(10,6)) plt.plot(lasso.alphas_, np.mean(lasso.mse_path_, axis=1), marker='o') plt.xlabel('Alpha') plt.ylabel('Mean Squared Error') plt.title('Cross-Validation MSE vs. Alpha') plt.show() # Model performance on test set y_pred = lasso.predict(X_test) test_mse = np.mean((y_pred - y_test) ** 2) print(f'Test Set MSE: {test_mse:.2f}')
Output:
yaml
Copy code
Lasso Regression Coefficients: self_esteem 0.36 depression -0.27 violence -0.22 gpa 0.18 family_connectedness 0.15 ... dtype: float64 Test Set MSE: 0.52
Interpretation
The lasso regression identified 18 predictors significantly associated with school connectedness among adolescents. The analysis highlighted the importance of self-esteem, depression, violence, and GPA as key predictors. These results suggest that interventions aimed at improving self-esteem and academic performance while addressing issues related to depression and violent behavior could enhance adolescents' sense of school connectedness.
The model’s cross-validated mean squared error plot showed that adding more variables beyond those selected did not substantially decrease the error, justifying the selected subset of predictors. The lasso regression approach effectively reduced the complexity of the model by excluding less important variables, thereby making it easier to interpret and apply the findings in a practical context.
0 notes
juliebowie · 18 days
Text
Learn The Art Of How To Tabulate Data in Python: Tips And Tricks
Summary: Master how to tabulate data in Python using essential libraries like Pandas and NumPy. This guide covers basic and advanced techniques, including handling missing data, multi-indexing, and creating pivot tables, enabling efficient Data Analysis and insightful decision-making.
Tumblr media
Introduction
In Data Analysis, mastering how to tabulate data in Python is akin to wielding a powerful tool for extracting insights. This article offers a concise yet comprehensive overview of this essential skill. Analysts and Data Scientists can efficiently organise and structure raw information by tabulating data, paving the way for deeper analysis and visualisation. 
Understanding the significance of tabulation lays the foundation for effective decision-making, enabling professionals to uncover patterns, trends, and correlations within datasets. Join us as we delve into the intricacies of data tabulation in Python, unlocking its potential for informed insights and impactful outcomes.
Getting Started with Data Tabulation Using Python
Tabulating data is a fundamental aspect of Data Analysis and is crucial in deriving insights and making informed decisions. With Python, a versatile and powerful programming language, you can efficiently tabulate data from various sources and formats. 
Whether working with small-scale datasets or handling large volumes of information, Python offers robust tools and libraries to streamline the tabulation process. Understanding the basics is essential when tabulating data using Python. In this section, we'll delve into the foundational concepts of data tabulation and explore how Python facilitates this task.
Basic Data Structures for Tabulation
Before diving into data tabulation techniques, it's crucial to grasp the basic data structures commonly used in Python. These data structures are the building blocks for effectively organising and manipulating data. The primary data structures for tabulation include lists, dictionaries, and data frames.
Lists: Lists are versatile data structures in Python that allow you to store and manipulate sequences of elements. They can contain heterogeneous data types and are particularly useful for tabulating small-scale datasets.
Dictionaries: Dictionaries are collections of key-value pairs that enable efficient data storage and retrieval. They provide a convenient way to organise tabulated data, especially when dealing with structured information.
DataFrames: These are a central data structure in libraries like Pandas, offering a tabular data format similar to a spreadsheet or database table. DataFrames  provide potent tools for tabulating and analysing data, making them a preferred choice for many Data Scientists and analysts.
Overview of Popular Python Libraries for Data Tabulation
Python boasts a rich ecosystem of libraries specifically designed for data manipulation and analysis. Two popular libraries for data tabulation are Pandas and NumPy.
Pandas: It is a versatile and user-friendly library that provides high-performance data structures and analysis tools. Pandas offers a DataFrame object and a wide range of functions for reading, writing, and manipulating tabulated data efficiently.
NumPy: It is a fundamental library for Python numerical computing. It provides support for large, multidimensional arrays and matrices. While not explicitly designed for tabulation, NumPy’s array-based operations are often used for data manipulation tasks with other libraries.
By familiarising yourself with these basic data structures and popular Python libraries, you'll be well-equipped to embark on your journey into data tabulation using Python.
Tabulating Data with Pandas
Pandas is a powerful Python library widely used for data manipulation and analysis. This section will delve into the fundamentals of tabulating data with Pandas, covering everything from installation to advanced operations.
Installing and Importing Pandas
Before tabulating data with Pandas, you must install the library on your system. Installation is typically straightforward using Python's package manager, pip. Open your command-line interface and execute the following command:
Tumblr media
Once Pandas is installed, you can import it into your Python scripts or notebooks using the `import` statement:
Tumblr media
Reading Data into Pandas DataFrame
Pandas provide various functions for reading data from different file formats such as CSV, Excel, SQL databases, etc. One of the most commonly used functions is `pd.read_csv()` for reading data from a CSV file into a Pandas DataFrame:
Tumblr media
You can replace `'data.csv'` with the path to your CSV file. Pandas automatically detect the delimiter and other parameters to load the data correctly.
Basic DataFrame Operations for Tabulation
Once your data is loaded into a data frame, you can perform various operations to tabulate and manipulate it. Some basic operations include:
Selecting Data: Use square brackets `[]` or the `.loc[]` and `.iloc[]` accessors to select specific rows and columns.
Filtering Data: Apply conditional statements to filter rows based on specific criteria using boolean indexing.
Sorting Data: Use the `.sort_values()` method to sort the DataFrame by one or more columns.
Grouping and Aggregating Data with Pandas
Grouping and aggregating data are essential techniques for summarising and analysing datasets. Pandas provides the `.groupby()` method for grouping data based on one or more columns. After grouping, you can apply aggregation functions such as `sum()`, `mean()`, `count()`, etc., to calculate statistics for each group.
Tumblr media
This code groups the DataFrame `df` by the 'category' column. It calculates the sum of the 'value' column for each group.
Mastering these basic operations with Pandas is crucial for efficient data tabulation and analysis in Python.
Advanced Techniques for Data Tabulation
Mastering data tabulation involves more than just basic operations. Advanced techniques can significantly enhance your data manipulation and analysis capabilities. This section explores how to handle missing data, perform multi-indexing, create pivot tables, and combine datasets for comprehensive tabulation.
Handling Missing Data in Tabulated Datasets
Missing data is a common issue in real-world datasets, and how you handle it can significantly affect your analysis. Python's Pandas library provides robust methods to manage missing data effectively.
First, identify missing data using the `isnull()` function, which helps locate NaNs in your DataFrame. You can then decide whether to remove or impute these values. Use `dropna()` to eliminate rows or columns with missing data. This method is straightforward but might lead to a significant data loss.
Alternatively, the `fillna()` method can fill missing values. This function allows you to replace NaNs with specific values, such as the mean and median, or a technique such as forward-fill or backward-fill. Choosing the right strategy depends on your dataset and analysis goals.
Performing Multi-Indexing and Hierarchical Tabulation
Multi-indexing, or hierarchical indexing, enables you to work with higher-dimensional data in a structured way. This technique is invaluable for managing complex datasets containing multiple information levels.
In Pandas, create a multi-index DataFrame by passing a list of arrays to the `set_index()` method. This approach allows you to perform operations across multiple levels. For instance, you can aggregate data at different levels using the `groupby()` function. Multi-indexing enhances your ability to navigate and analyse data hierarchically, making it easier to extract meaningful insights.
Pivot Tables for Advanced Data Analysis
Pivot tables are potent tools for summarising and reshaping data, making them ideal for advanced Data Analysis. You can create pivot tables in Python using Pandas `pivot_table()` function.
A pivot table lets you group data by one or more keys while applying an aggregate function, such as sum, mean, or count. This functionality simplifies data comparison and trend identification across different dimensions. By specifying parameters like `index`, `columns`, and `values`, you can customise the table to suit your analysis needs.
Combining and Merging Datasets for Comprehensive Tabulation
Combining and merging datasets is essential when dealing with fragmented data sources. Pandas provides several functions to facilitate this process, including `concat()`, `merge()`, and `join()`.
Use `concat()` to append or stack DataFrames vertically or horizontally. This function helps add new data to an existing dataset. Like SQL joins, the `merge()` function combines datasets based on standard columns or indices. This method is perfect for integrating related data from different sources. The `join()` function offers a more straightforward way to merge datasets on their indices, simplifying the combination process.
These advanced techniques can enhance your data tabulation skills, leading to more efficient and insightful Data Analysis.
Tips and Tricks for Efficient Data Tabulation
Efficient data tabulation in Python saves time and enhances the quality of your Data Analysis. Here, we'll delve into some essential tips and tricks to optimise your data tabulation process.
Utilising Vectorised Operations for Faster Tabulation
Vectorised operations in Python, particularly with libraries like Pandas and NumPy, can significantly speed up data tabulation. These operations allow you to perform computations on entire arrays or DataFrames without explicit loops.
You can leverage the underlying C and Fortran code in these libraries using vectorised operations, much faster than Python's native loops. For instance, consider adding two columns in a DataFrame. Instead of using a loop to iterate through each row, you can simply use:
Tumblr media
This one-liner makes your code more concise and drastically reduces execution time. Embrace vectorisation whenever possible to maximise efficiency.
Optimising Memory Usage When Working with Large Datasets
Large datasets can quickly consume your system's memory, leading to slower performance or crashes. Optimising memory usage is crucial for efficient data tabulation.
One effective approach is to use appropriate data types for your columns. For instance, if you have a column of integers that only contains values from 0 to 255, using the `int8` data type instead of the default `int64` can save substantial memory. Here's how you can optimise a DataFrame:
Tumblr media
Additionally, consider using chunking techniques when reading large files. Instead of loading the entire dataset at once, process it in smaller chunks:
Tumblr media
This method ensures you never exceed your memory capacity, maintaining efficient data processing.
Customising Tabulated Output for Readability and Presentation
Presenting your tabulated data is as important as the analysis itself. Customising the output can enhance readability and make your insights more accessible.
Start by formatting your DataFrame using Pandas' built-in styling functions. You can highlight important data points, format numbers, and even create colour gradients. For example:
Tumblr media
Additionally, when exporting data to formats like CSV or Excel, ensure that headers and index columns are appropriately labelled. Use the `to_csv` and `to_excel` methods with options for customisation:
Tumblr media
These small adjustments can significantly improve the presentation quality of your tabulated data.
Leveraging Built-in Functions and Methods for Streamlined Tabulation
Python libraries offer many built-in functions and methods that simplify and expedite the tabulation process. Pandas, in particular, provide powerful tools for data manipulation.
For instance, the `groupby` method allows you to group data by specific columns and perform aggregate functions such as sum, mean, or count:
Tumblr media
Similarly, the `pivot_table` method lets you create pivot tables, which are invaluable for summarising and analysing large datasets.
Mastering these built-in functions can streamline your data tabulation workflow, making it faster and more effective.
Incorporating these tips and tricks into your data tabulation process will enhance efficiency, optimise resource usage, and improve the clarity of your presented data, ultimately leading to more insightful and actionable analysis.
Read More: 
Data Abstraction and Encapsulation in Python Explained.
Anaconda vs Python: Unveiling the differences.
Frequently Asked Questions
What Are The Basic Data Structures For Tabulating Data In Python?
Lists, dictionaries, and DataFrames are the primary data structures for tabulating data in Python. Lists store sequences of elements, dictionaries manage key-value pairs, and DataFrames, available in the Pandas library, offer a tabular format for efficient Data Analysis.
How Do You Handle Missing Data In Tabulated Datasets Using Python?
To manage missing data in Python, use Pandas' `isnull()` to identify NaNs. Then, use `dropna()` to remove them or `fillna()` to replace them with appropriate values like the mean or median, ensuring data integrity.
What Are Some Advanced Techniques For Data Tabulation In Python?
Advanced tabulation techniques in Python include handling missing data, performing multi-indexing for hierarchical data, creating pivot tables for summarisation, and combining datasets using functions like `concat()`, `merge()`, and `join()` for comprehensive Data Analysis.
Conclusion
Mastering how to tabulate data in Python is essential for Data Analysts and scientists. Professionals can efficiently organise, manipulate, and analyse data by understanding and utilising Python's powerful libraries, such as Pandas and NumPy. 
Techniques like handling missing data, multi-indexing, and creating pivot tables enhance the depth of analysis. Efficient data tabulation saves time and optimises memory usage, leading to more insightful and actionable outcomes. Embracing these skills will significantly improve data-driven decision-making processes.
0 notes
mengchunhsieh · 19 days
Text
K-means clusthering
#importamos las librerías necesarias
from pandas import Series,DataFrame
import pandas as pd
import numpy as np
import matplotlib.pylab as plt
from sklearn.model_selection
import train_test_splitfrom sklearn
import preprocessing
from sklearn.cluster import KMeans
"""Data Management"""
data =pd.read_csv("/content/drive/MyDrive/tree_addhealth.csv" )
#upper-case all DataFrame column names
data.columns = map(str.upper, data.columns)
# Data Managementdata_clean = data.dropna()
# subset clustering variablescluster=data_clean[['ALCEVR1','MAREVER1','ALCPROBS1','DEVIANT1','VIOL1','DEP1','ESTEEM1','SCHCONN1','PARACTV', 'PARPRES','FAMCONCT']]
cluster.describe()
# standardize clustering variables to have mean=0 and sd=1
clustervar=cluster.copy()
clustervar['ALCEVR1']=preprocessing.scale(clustervar['ALCEVR1'].astype('float64'))
clustervar['ALCPROBS1']=preprocessing.scale(clustervar['ALCPROBS1'].astype('float64'))
clustervar['MAREVER1']=preprocessing.scale(clustervar['MAREVER1'].astype('float64'))
clustervar['DEP1']=preprocessing.scale(clustervar['DEP1'].astype('float64'))
clustervar['ESTEEM1']=preprocessing.scale(clustervar['ESTEEM1'].astype('float64'))
clustervar['VIOL1']=preprocessing.scale(clustervar['VIOL1'].astype('float64'))
clustervar['DEVIANT1']=preprocessing.scale(clustervar['DEVIANT1'].astype('float64'))
clustervar['FAMCONCT']=preprocessing.scale(clustervar['FAMCONCT'].astype('float64'))
clustervar['SCHCONN1']=preprocessing.scale(clustervar['SCHCONN1'].astype('float64'))
clustervar['PARACTV']=preprocessing.scale(clustervar['PARACTV'].astype('float64'))
clustervar['PARPRES']=preprocessing.scale(clustervar['PARPRES'].astype('float64'))
# split data into train and test sets
clus_train, clus_test = train_test_split(clustervar, test_size=.3, random_state=123)
# k-means cluster analysis for 1-9 clusters
from scipy.spatial.distance import cdist
clusters=range(1,10)
meandist=[]
for k in clusters: model=KMeans(n_clusters=k) model.fit(clus_train) clusassign=model.predict(clus_train) meandist.append(sum(np.min(cdist(clus_train, model.cluster_centers_, 'euclidean'), axis=1))
/ clus_train.shape[0])
"""Plot average distance from observations from the cluster centroidto use the Elbow Method to identify number of clusters to choose"""
plt.plot(clusters,meandist)
plt.xlabel('Number of clusters')
plt.ylabel('Average distance')
plt.title('Selecting k with the Elbow Method')
# Interpret 2 cluster solution
model2=KMeans(n_clusters=2)model2.fit(clus_train)
clusassign=model2.predict(clus_train)
# plot clusters
from sklearn.decomposition import PCA
pca_2 = PCA(2)
plot_columns = pca_2.fit_transform(clus_train)
plt.scatter(x=plot_columns[:,0],y=plot_columns[:,1],c=model2.labels_,)
plt.xlabel('Canonical variable 1')
plt.ylabel('Canonical variable 2')
plt.title('Scatterplot of Canonical Variables for 2 Clusters')
plt.show()
"""BEGIN multiple steps to merge cluster assignment with clustering variables to examinecluster variable means by cluster"""
# create a unique identifier variable from the index for the
# cluster training data to merge with the cluster assignment variable
clus_train.reset_index(level=0, inplace=True)
# create a list that has the new index variable
cluslist=list(clus_train['index'])
# create a list of cluster assignments
labels=list(model2.labels_)
# combine index variable list with cluster assignment list into a dictionary
newlist=dict(zip(cluslist, labels))newlist
# convert newlist dictionary to a dataframenew
clus=DataFrame.from_dict(newlist, orient='index')newclus
# rename the cluster assignment columnnew
clus.columns = ['cluster']
# now do the same for the cluster assignment variable
# create a unique identifier variable from the index for the
# cluster assignment dataframe
# to merge with cluster training datanew
clus.reset_index(level=0, inplace=True)
# merge the cluster assignment dataframe with the cluster training variable dataframe
# by the index variablemerged_train=pd.merge(clus_train, newclus, on='index')
merged_train.head(n=100)
# cluster frequenciesmerged_train.cluster.value_counts()
"""END multiple steps to merge cluster assignment with clustering variables to examinecluster variable means by cluster"""
# FINALLY calculate clustering variable means by
clusterclustergrp = merged_train.groupby('cluster').mean()print ("Clustering variable means by cluster")
print(clustergrp)
# validate clusters in training data by examining cluster differences in GPA using ANOVA
# first have to merge GPA with clustering variables and cluster assignment data
gpa_data=data_clean['GPA1']
# split GPA data into train and test sets
gpa_train, gpa_test = train_test_split(gpa_data, test_size=.3, random_state=123)
gpa_train1=pd.DataFrame(gpa_train)
gpa_train1.reset_index(level=0, inplace=True)
merged_train_all=pd.merge(gpa_train1, merged_train, on='index')
sub1 = merged_train_all[['GPA1', 'cluster']].dropna()
import statsmodels.formula.api as smf
import statsmodels.stats.multicomp as multi
gpamod = smf.ols(formula='GPA1 ~ C(cluster)', data=sub1).fit()
print (gpamod.summary())
print ('means for GPA by cluster')
m1= sub1.groupby('cluster').mean()
print (m1)
print ('standard deviations for GPA by cluster')
m2= sub1.groupby('cluster').std()print (m2)
mc1 = multi.MultiComparison(sub1['GPA1'], sub1['cluster'])
res1 = mc1.tukeyhsd()
print(res1.summary())
Tumblr media
爆發
0 則迴響
0 notes
rogerscode · 21 days
Text
K-means clusthering
#importamos las librerías necesarias
from pandas import Series,DataFrame
import pandas as pd
import numpy as np
import matplotlib.pylab as plt
from sklearn.model_selection
import train_test_splitfrom sklearn
import preprocessing
from sklearn.cluster import KMeans
"""Data Management"""
data =pd.read_csv("/content/drive/MyDrive/tree_addhealth.csv" )
#upper-case all DataFrame column names
data.columns = map(str.upper, data.columns)
# Data Managementdata_clean = data.dropna()
# subset clustering variablescluster=data_clean[['ALCEVR1','MAREVER1','ALCPROBS1','DEVIANT1','VIOL1','DEP1','ESTEEM1','SCHCONN1','PARACTV', 'PARPRES','FAMCONCT']]
cluster.describe()
# standardize clustering variables to have mean=0 and sd=1
clustervar=cluster.copy()
clustervar['ALCEVR1']=preprocessing.scale(clustervar['ALCEVR1'].astype('float64'))
clustervar['ALCPROBS1']=preprocessing.scale(clustervar['ALCPROBS1'].astype('float64'))
clustervar['MAREVER1']=preprocessing.scale(clustervar['MAREVER1'].astype('float64'))
clustervar['DEP1']=preprocessing.scale(clustervar['DEP1'].astype('float64'))
clustervar['ESTEEM1']=preprocessing.scale(clustervar['ESTEEM1'].astype('float64'))
clustervar['VIOL1']=preprocessing.scale(clustervar['VIOL1'].astype('float64'))
clustervar['DEVIANT1']=preprocessing.scale(clustervar['DEVIANT1'].astype('float64'))
clustervar['FAMCONCT']=preprocessing.scale(clustervar['FAMCONCT'].astype('float64'))
clustervar['SCHCONN1']=preprocessing.scale(clustervar['SCHCONN1'].astype('float64'))
clustervar['PARACTV']=preprocessing.scale(clustervar['PARACTV'].astype('float64'))
clustervar['PARPRES']=preprocessing.scale(clustervar['PARPRES'].astype('float64'))
# split data into train and test sets
clus_train, clus_test = train_test_split(clustervar, test_size=.3, random_state=123)
# k-means cluster analysis for 1-9 clusters
from scipy.spatial.distance import cdist
clusters=range(1,10)
meandist=[]
for k in clusters: model=KMeans(n_clusters=k) model.fit(clus_train) clusassign=model.predict(clus_train) meandist.append(sum(np.min(cdist(clus_train, model.cluster_centers_, 'euclidean'), axis=1))
/ clus_train.shape[0])
"""Plot average distance from observations from the cluster centroidto use the Elbow Method to identify number of clusters to choose"""
plt.plot(clusters,meandist)
plt.xlabel('Number of clusters')
plt.ylabel('Average distance')
plt.title('Selecting k with the Elbow Method')
# Interpret 2 cluster solution
model2=KMeans(n_clusters=2)model2.fit(clus_train)
clusassign=model2.predict(clus_train)
# plot clusters
from sklearn.decomposition import PCA
pca_2 = PCA(2)
plot_columns = pca_2.fit_transform(clus_train)
plt.scatter(x=plot_columns[:,0],y=plot_columns[:,1],c=model2.labels_,)
plt.xlabel('Canonical variable 1')
plt.ylabel('Canonical variable 2')
plt.title('Scatterplot of Canonical Variables for 2 Clusters')
plt.show()
"""BEGIN multiple steps to merge cluster assignment with clustering variables to examinecluster variable means by cluster"""
# create a unique identifier variable from the index for the
# cluster training data to merge with the cluster assignment variable
clus_train.reset_index(level=0, inplace=True)
# create a list that has the new index variable
cluslist=list(clus_train['index'])
# create a list of cluster assignments
labels=list(model2.labels_)
# combine index variable list with cluster assignment list into a dictionary
newlist=dict(zip(cluslist, labels))newlist
# convert newlist dictionary to a dataframenew
clus=DataFrame.from_dict(newlist, orient='index')newclus
# rename the cluster assignment columnnew
clus.columns = ['cluster']
# now do the same for the cluster assignment variable
# create a unique identifier variable from the index for the
# cluster assignment dataframe
# to merge with cluster training datanew
clus.reset_index(level=0, inplace=True)
# merge the cluster assignment dataframe with the cluster training variable dataframe
# by the index variablemerged_train=pd.merge(clus_train, newclus, on='index')
merged_train.head(n=100)
# cluster frequenciesmerged_train.cluster.value_counts()
"""END multiple steps to merge cluster assignment with clustering variables to examinecluster variable means by cluster"""
# FINALLY calculate clustering variable means by
clusterclustergrp = merged_train.groupby('cluster').mean()print ("Clustering variable means by cluster")
print(clustergrp)
# validate clusters in training data by examining cluster differences in GPA using ANOVA
# first have to merge GPA with clustering variables and cluster assignment data
gpa_data=data_clean['GPA1']
# split GPA data into train and test sets
gpa_train, gpa_test = train_test_split(gpa_data, test_size=.3, random_state=123)
gpa_train1=pd.DataFrame(gpa_train)
gpa_train1.reset_index(level=0, inplace=True)
merged_train_all=pd.merge(gpa_train1, merged_train, on='index')
sub1 = merged_train_all[['GPA1', 'cluster']].dropna()
import statsmodels.formula.api as smf
import statsmodels.stats.multicomp as multi
gpamod = smf.ols(formula='GPA1 ~ C(cluster)', data=sub1).fit()
print (gpamod.summary())
print ('means for GPA by cluster')
m1= sub1.groupby('cluster').mean()
print (m1)
print ('standard deviations for GPA by cluster')
m2= sub1.groupby('cluster').std()print (m2)
mc1 = multi.MultiComparison(sub1['GPA1'], sub1['cluster'])
res1 = mc1.tukeyhsd()
print(res1.summary())
Tumblr media Tumblr media
Tumblr media Tumblr media
0 notes
computercodingclass · 1 month
Text
How to Transpose a DataFrame in Python Without Index | Python Pandas Tutorial for Beginners
via IFTTT
youtube
View On WordPress
0 notes
slushys-world · 2 months
Text
```python
from moviepy.editor import TextClip, concatenate_videoclips, CompositeVideoClip
import pandas as pd
# Data about the scenes
data = {
'text': [
"A person who deceives and manipulates.",
"Someone who uses others for personal gain.",
"A character lacking honesty and loyalty."
],
'duration': [3, 3, 3], # Duration of each clip in seconds
'fontsize': [50, 50, 50],
'color': ['white', 'white', 'white'],
'bg_color': ['black', 'red', 'grey']
}
df = pd.DataFrame(data)
# Create a list to hold video clips
clips = []
# Generate a text clip for each entry in the DataFrame
for index, row in df.iterrows():
txt_clip = TextClip(row['text'], fontsize=row['fontsize'], color=row['color'], bg_color=row['bg_color'], size=(1920, 1080))
txt_clip = txt_clip.set_duration(row['duration'])
clips.append(txt_clip)
# Concatenate all clips into one video
final_clip = concatenate_videoclips(clips, method="compose")
# Write the result to a file
final_clip.write_videofile("reel.mp4", fps=24)
```
1 note · View note
edcater · 2 months
Text
Data Science Made Easy: Python Essentials for Beginners
In today's data-driven world, the ability to extract valuable insights from vast amounts of information is crucial for businesses and individuals alike. Data science has emerged as a powerful discipline that combines statistical analysis, machine learning, and domain expertise to uncover patterns, make predictions, and drive decision-making. And at the heart of data science lies Python, a versatile programming language renowned for its simplicity and effectiveness in handling data. In this article, we will explore the fundamentals of Python for data science, catering to beginners with easy-to-understand explanations and practical examples.
1. Why Python for Data Science?
Python has become the lingua franca of data science for several compelling reasons. Firstly, its syntax is clear and concise, making it easy for beginners to learn and understand. Secondly, Python boasts a vast ecosystem of libraries specifically designed for data manipulation, analysis, and visualization, such as NumPy, Pandas, and Matplotlib. Thirdly, Python's versatility extends beyond data science, allowing users to seamlessly integrate their data analysis workflows with web development, automation, and more.
2. Getting Started with Python
Before diving into data science applications, it's essential to familiarize yourself with Python basics. Fortunately, Python's gentle learning curve makes it accessible even to those with little to no programming experience. Start by installing Python on your computer and exploring its interactive shell, where you can execute commands and see immediate results. Learn about variables, data types, and control structures like loops and conditional statements, as they form the building blocks of Python programming.
3. Handling Data with NumPy
NumPy, short for Numerical Python, is a fundamental library for scientific computing in Python. It provides powerful tools for working with multidimensional arrays and performing mathematical operations efficiently. Whether you're crunching numbers, manipulating matrices, or generating random data, NumPy's array-oriented computing capabilities streamline the process and enhance performance. Familiarize yourself with NumPy arrays, indexing, slicing, and broadcasting to unleash the full potential of data manipulation in Python.
4. Data Wrangling with Pandas
Pandas is a game-changer for data manipulation and analysis in Python. Built on top of NumPy, Pandas introduces the DataFrame data structure, which resembles a spreadsheet and enables intuitive handling of structured data. With Pandas, you can load data from various sources, clean and preprocess it, perform aggregations and transformations, and handle missing values effortlessly. Mastering Pandas' functionality, including filtering, grouping, and merging operations, empowers you to tackle real-world data challenges with ease.
5. Visualizing Insights with Matplotlib
Data visualization is a powerful tool for communicating findings and uncovering patterns in data. Matplotlib, a widely-used plotting library in Python, offers a plethora of customizable options for creating static, interactive, and publication-quality visualizations. Whether you're plotting histograms, scatter plots, or time series, Matplotlib's intuitive interface and extensive documentation make it easy to generate informative graphics. Experiment with different plot types, styles, and annotations to craft compelling visual narratives from your data.
6. Exploring Data Science Libraries
Beyond NumPy, Pandas, and Matplotlib, Python boasts a rich ecosystem of specialized libraries tailored to various aspects of data science. For statistical analysis, SciPy provides advanced functions and algorithms for optimization, integration, and interpolation. Scikit-learn offers a comprehensive toolkit for machine learning tasks, including classification, regression, clustering, and dimensionality reduction. TensorFlow and PyTorch are go-to choices for deep learning enthusiasts, offering flexible frameworks for building and training neural networks.
7. Leveraging Jupyter Notebooks
Jupyter Notebooks revolutionize the way data scientists work by combining code, visualizations, and explanatory text in a single interactive document. With Jupyter, you can iteratively explore data, experiment with algorithms, and annotate your findings in a collaborative and reproducible manner. Its support for various programming languages, including Python, R, and Julia, makes it a versatile tool for interdisciplinary research and education. Get comfortable with Jupyter's interface, keyboard shortcuts, and Markdown syntax to streamline your data science workflows.
8. Embracing Best Practices
As you delve deeper into the realm of data science with Python, it's essential to adopt best practices to ensure efficiency, reliability, and maintainability of your code. Write clear and concise code with meaningful variable names and comments to enhance readability and comprehension. Document your workflows and analyses using Markdown, reStructuredText, or Jupyter's Markdown cells to provide context and explanations for future reference. Embrace version control systems like Git to track changes, collaborate with colleagues, and revert to previous states when necessary.
9. Continuing Your Learning Journey
Python for data science is a vast and ever-evolving field, and there's always something new to learn and explore. Stay curious and proactive by seeking out online tutorials, courses, and books that cater to your specific interests and learning style. Engage with the vibrant Python community through forums, meetups, and social media platforms to exchange ideas, ask questions, and share insights with fellow enthusiasts. And most importantly, embrace a growth mindset and approach each challenge as an opportunity to expand your knowledge and skills in Python and data science.
In conclusion, Python serves as an indispensable tool for aspiring data scientists, offering a user-friendly yet powerful platform for data manipulation, analysis, and visualization. By mastering Python essentials and leveraging its rich ecosystem of libraries and tools, beginners can embark on a rewarding journey into the fascinating world of data science. With practice, persistence, and a passion for discovery, anyone can unlock the transformative potential of Python in their data-driven endeavors.
0 notes
iwebscrapingblogs · 2 months
Text
How To Scrape Walmart for Product Information Using Python
Tumblr media
In the ever-expanding world of e-commerce, Walmart is one of the largest retailers, offering a wide variety of products across numerous categories. If you're a data enthusiast, researcher, or business owner, you might find it useful to scrape Walmart for product information such as prices, product descriptions, and reviews. In this blog post, I'll guide you through the process of scraping Walmart's website using Python, covering the tools and libraries you'll need as well as the code to get started.
Why Scrape Walmart?
There are several reasons you might want to scrape Walmart's website:
Market research: Analyze competitor prices and product offerings.
Data analysis: Study trends in consumer preferences and purchasing habits.
Product monitoring: Track changes in product availability and prices over time.
Business insights: Understand what products are most popular and how they are being priced.
Tools and Libraries
To get started with scraping Walmart's website, you'll need the following tools and libraries:
Python: The primary programming language we'll use for this task.
Requests: A Python library for making HTTP requests.
BeautifulSoup: A Python library for parsing HTML and XML documents.
Pandas: A data manipulation library to organize and analyze the scraped data.
First, install the necessary libraries:
shell
Copy code
pip install requests beautifulsoup4 pandas
How to Scrape Walmart
Let's dive into the process of scraping Walmart's website. We'll focus on scraping product information such as title, price, and description.
1. Import Libraries
First, import the necessary libraries:
python
Copy code
import requests from bs4 import BeautifulSoup import pandas as pd
2. Define the URL
You need to define the URL of the Walmart product page you want to scrape. For this example, we'll use a sample URL:
python
Copy code
url = "https://www.walmart.com/search/?query=laptop"
You can replace the URL with the one you want to scrape.
3. Send a Request and Parse the HTML
Next, send an HTTP GET request to the URL and parse the HTML content using BeautifulSoup:
python
Copy code
response = requests.get(url) soup = BeautifulSoup(response.text, "html.parser")
4. Extract Product Information
Now, let's extract the product information from the HTML content. We will focus on extracting product titles, prices, and descriptions.
Here's an example of how to do it:
python
Copy code
# Create lists to store the scraped data product_titles = [] product_prices = [] product_descriptions = [] # Find the product containers on the page products = soup.find_all("div", class_="search-result-gridview-item") # Loop through each product container and extract the data for product in products: # Extract the title title = product.find("a", class_="product-title-link").text.strip() product_titles.append(title) # Extract the price price = product.find("span", class_="price-main-block").find("span", class_="visuallyhidden").text.strip() product_prices.append(price) # Extract the description description = product.find("span", class_="price-characteristic").text.strip() if product.find("span", class_="price-characteristic") else "N/A" product_descriptions.append(description) # Create a DataFrame to store the data data = { "Product Title": product_titles, "Price": product_prices, "Description": product_descriptions } df = pd.DataFrame(data) # Display the DataFrame print(df)
In the code above, we loop through each product container and extract the title, price, and description of each product. The data is stored in lists and then converted into a Pandas DataFrame for easy data manipulation and analysis.
5. Save the Data
Finally, you can save the extracted data to a CSV file or any other desired format:
python
Copy code
df.to_csv("walmart_products.csv", index=False)
Conclusion
Scraping Walmart for product information can provide valuable insights for market research, data analysis, and more. By using Python libraries such as Requests, BeautifulSoup, and Pandas, you can extract data efficiently and save it for further analysis. Remember to use this information responsibly and abide by Walmart's terms of service and scraping policies.
0 notes
tom30305 · 3 months
Text
34
Summary of Findings in Logistic Regression Analysis:
In the logistic regression analysis, after adjusting for potential confounding factors, I found significant associations between the explanatory variables and the response variable. Specifically, individuals with higher BMI were found to have a higher likelihood of belonging to the positive class of the response variable (OR = 1.72, 95% CI = 1.23-2.41, p = 0.001). Similarly, older age was associated with a decreased likelihood of belonging to the positive class (OR = 0.64, 95% CI = 0.46-0.87, p = 0.006). Additionally, gender also showed a significant association with the likelihood of belonging to the positive class, with males having a higher likelihood compared to females (OR = 1.48, 95% CI = 1.05-2.09, p = 0.025).
Hypothesis Confirmation:
The results support the hypothesis that BMI, age, and gender are associated with the likelihood of belonging to the positive class of the response variable. The statistically significant odds ratios (ORs) and their 95% confidence intervals (CIs) indicate that these relationships are unlikely to be due to random chance.
Evidence of Confounding:
After adjusting for potential confounding factors, such as socioeconomic status or lifestyle factors, the associations between BMI, age, gender, and the likelihood of belonging to the positive class remained significant. This suggests that these variables are independently associated with the likelihood of belonging to the positive class, even after accounting for other potential confounding factors.
Conclusion:
In conclusion, the logistic regression analysis reveals that BMI, age, and gender are significant predictors of the likelihood of belonging to the positive class of the response variable. These findings underscore the importance of considering multiple demographic and physiological factors when studying the relationship between these variables and the response variable.
code:
import pandas as pd import numpy as np import statsmodels.api as sm
findings_data = pd.DataFrame({ 'variable': ['BMI', 'age', 'gender_male'], 'coef': [1.72, -0.64, 1.48], # Coefficients from the logistic regression analysis 'p_value': [0.001, 0.006, 0.025] # p-values from the logistic regression analysis })
print("Summary of Findings in Logistic Regression Analysis:") for index, row in findings_data.iterrows(): print(f"{row['variable'].capitalize()}: OR = {row['coef']:.2f}, 95% CI = (", np.exp(row['coef'] - 1.96 * np.sqrt(0.001 * (1 - 0.001))), ",", np.exp(row['coef'] + 1.96 * np.sqrt(0.001 * (1 - 0.001))), f"), p = {row['p_value']:.3f}")
print("\nHypothesis Confirmation:") print("The results support the hypothesis that BMI, age, and gender are associated with the likelihood of belonging to the positive class of the response variable.")
print("\nEvidence of Confounding:") print("After adjusting for potential confounding factors, such as socioeconomic status or lifestyle factors, the associations between BMI, age, gender, and the likelihood of belonging to the positive class remained significant.")
print("\nConclusion:") print("In conclusion, the logistic regression analysis reveals that BMI, age, and gender are significant predictors of the likelihood of belonging to the positive class of the response variable.")
This code demonstrates the summarized findings in a logistic regression analysis by creating a DataFrame with coefficients and p-values, then printing the findings along with the confirmation of hypothesis and evidence of confounding. Finally, it concludes the analysis. Adjust the variable names and values according to your actual analysis.
0 notes
deba1407 · 6 months
Text
KMeans Clustering Assignment
Import the modules
from pandas import Series, DataFrame import pandas as pd import numpy as np import matplotlib.pylab as plt from sklearn.model_selection import train_test_split from sklearn import preprocessing from sklearn.cluster import KMeans
Load the dataset
data = pd.read_csv("C:\Users\guy3404\OneDrive - MDLZ\Documents\Cross Functional Learning\AI COP\Coursera\machine_learning_data_analysis\Datasets\tree_addhealth.csv")
data.head()
Tumblr media
upper-case all DataFrame column names
data.columns = map(str.upper, data.columns)
Data Management
data_clean = data.dropna() data_clean.head()
subset clustering variables
cluster=data_clean[['ALCEVR1','MAREVER1','ALCPROBS1','DEVIANT1','VIOL1', 'DEP1','ESTEEM1','SCHCONN1','PARACTV', 'PARPRES','FAMCONCT']] cluster.describe()
Tumblr media
standardize clustering variables to have mean=0 and sd=1
clustervar=cluster.copy() clustervar['ALCEVR1']=preprocessing.scale(clustervar['ALCEVR1'].astype('float64')) clustervar['ALCPROBS1']=preprocessing.scale(clustervar['ALCPROBS1'].astype('float64')) clustervar['MAREVER1']=preprocessing.scale(clustervar['MAREVER1'].astype('float64')) clustervar['DEP1']=preprocessing.scale(clustervar['DEP1'].astype('float64')) clustervar['ESTEEM1']=preprocessing.scale(clustervar['ESTEEM1'].astype('float64')) clustervar['VIOL1']=preprocessing.scale(clustervar['VIOL1'].astype('float64')) clustervar['DEVIANT1']=preprocessing.scale(clustervar['DEVIANT1'].astype('float64')) clustervar['FAMCONCT']=preprocessing.scale(clustervar['FAMCONCT'].astype('float64')) clustervar['SCHCONN1']=preprocessing.scale(clustervar['SCHCONN1'].astype('float64')) clustervar['PARACTV']=preprocessing.scale(clustervar['PARACTV'].astype('float64')) clustervar['PARPRES']=preprocessing.scale(clustervar['PARPRES'].astype('float64'))
split data into train and test sets
clus_train, clus_test = train_test_split(clustervar, test_size=.3, random_state=123)
k-means cluster analysis for 1-9 clusters
from scipy.spatial.distance import cdist clusters=range(1,10) meandist=[]
for k in clusters: model=KMeans(n_clusters=k) model.fit(clus_train) clusassign=model.predict(clus_train) meandist.append(sum(np.min(cdist(clus_train, model.cluster_centers_, 'euclidean'), axis=1)) / clus_train.shape[0])
""" Plot average distance from observations from the cluster centroid to use the Elbow Method to identify number of clusters to choose """ plt.plot(clusters, meandist) plt.xlabel('Number of clusters') plt.ylabel('Average distance') plt.title('Selecting k with the Elbow Method')
Tumblr media
Interpret 3 cluster solution
model3=KMeans(n_clusters=3) model3.fit(clus_train) clusassign=model3.predict(clus_train)
plot clusters
from sklearn.decomposition import PCA pca_2 = PCA(2) plot_columns = pca_2.fit_transform(clus_train) plt.scatter(x=plot_columns[:,0], y=plot_columns[:,1], c=model3.labels_,) plt.xlabel('Canonical variable 1') plt.ylabel('Canonical variable 2') plt.title('Scatterplot of Canonical Variables for 3 Clusters') plt.show()
Tumblr media
The datapoints of the 2 clusters in the left are less spread out but have more overlaps. The cluster to the right is more distinct but has more spread in the data points
""" BEGIN multiple steps to merge cluster assignment with clustering variables to examine cluster variable means by cluster """
create a unique identifier variable from the index for the
cluster training data to merge with the cluster assignment variable
clus_train.reset_index(level=0, inplace=True)
create a list that has the new index variable
cluslist=list(clus_train['index'])
create a list of cluster assignments
labels=list(model3.labels_)
combine index variable list with cluster assignment list into a dictionary
newlist=dict(zip(cluslist, labels)) newlist
convert newlist dictionary to a dataframe
newclus=DataFrame.from_dict(newlist, orient='index') newclus
rename the cluster assignment column
newclus.columns = ['cluster']
now do the same for the cluster assignment variable
create a unique identifier variable from the index for the
cluster assignment dataframe
to merge with cluster training data
newclus.reset_index(level=0, inplace=True)
merge the cluster assignment dataframe with the cluster training variable dataframe
by the index variable
merged_train=pd.merge(clus_train, newclus, on='index') merged_train.head(n=100)
cluster frequencies
merged_train.cluster.value_counts()
Tumblr media
""" END multiple steps to merge cluster assignment with clustering variables to examine cluster variable means by cluster """
FINALLY calculate clustering variable means by cluster
clustergrp = merged_train.groupby('cluster').mean() print ("Clustering variable means by cluster") print(clustergrp)
Tumblr media
validate clusters in training data by examining cluster differences in GPA using ANOVA
first have to merge GPA with clustering variables and cluster assignment data
gpa_data=data_clean['GPA1']
split GPA data into train and test sets
gpa_train, gpa_test = train_test_split(gpa_data, test_size=.3, random_state=123) gpa_train1=pd.DataFrame(gpa_train) gpa_train1.reset_index(level=0, inplace=True) merged_train_all=pd.merge(gpa_train1, merged_train, on='index') sub1 = merged_train_all[['GPA1', 'cluster']].dropna()
Print statistical summary by cluster
import statsmodels.formula.api as smf import statsmodels.stats.multicomp as multi
gpamod = smf.ols(formula='GPA1 ~ C(cluster)', data=sub1).fit() print (gpamod.summary())
print ('means for GPA by cluster') m1= sub1.groupby('cluster').mean() print (m1)
print ('standard deviations for GPA by cluster') m2= sub1.groupby('cluster').std() print (m2)
Tumblr media Tumblr media
Interpretation
The clustering average summary shows Cluster 0 has higher alcohol and marijuana problems, shows higher deviant and violent behavior, suffers from depression, has low self esteem,school connectedness, paraental and family connectedness. On the contrary, Cluster 2 shows the lowest alcohol and marijuana problems, lowest deviant & violent behavior,depression, and higher self esteem,school connectedness, paraental and family connectedness. Further, when validated against GPA score, we observe Cluster 0 shows the lowest average GPA and CLuster 2 has the highest average GPA which aligns with the summary statistics interpretation.
0 notes
sparkouttech · 6 months
Text
Top 9 Python Libraries for Machine Learning 
Tumblr media
Why Python for Machine Learning?
Python's open source libraries are not the only feature that makes it favorable for machine learning and AI tasks. Python is also very versatile and flexible, meaning it can also be used alongside other programming languages ​​when needed. 
Implementing deep neural networks and machine learning algorithms can be time-consuming, but Python offers many packages that reduce this. It is also an object-oriented programming (OOP) language, making it extremely useful for efficient use and categorization of data. 
Python has become a favorable programming language mostly for beginners because it is a growing community of users. Python developers and software development services  have skyrocketed as python became the fastest growing programming languages ​​in the world. The Python community is growing along with the language, with active members always looking to use it to address new problems in business.
9 best Python libraries for machine learning 
1. Science
NumPy is the foundation for SciPy, a free and open source library. It is especially useful for large data sets, being able to perform scientific and technical computing. 
The programming language includes all the features of NumPy, but turns them into easy-to-use scientific tools. It offers fundamental processing capabilities for complex, non-scientific mathematical operations and is frequently used for image manipulation.
SciPy is one of the fundamental Python libraries thanks to its role in scientific analysis and engineering. 
Features:
Easy to use.
Data visualization and manipulation.
Scientific and technical analysis. 
Calculate large data sets. 
2. Theano
Theano is a numerical computing Python library specifically developed for machine learning. It allows the optimization, definition and evaluation of mathematical expressions and matrix calculations. This allows the use of dimensional matrices to build deep learning models. 
Theano is a very specific library, and is mainly used by machine learning and deep learning developers and programmers. It supports integration with NumPy and can be used with a graphics processing unit (GPU) instead of a central processing unit (CPU), resulting in 140x faster data-intensive calculations. 
Features of Theano:
Integrated validation and unit testing tools.
Fast and stable evaluations.
Data-intensive calculations.
High-performance mathematical calculations.
3. Pandas
Another of the best Python libraries on the market is Pandas, which is often used for machine learning. It acts as a data analysis library that analyzes and manipulates data, and allows enterprise software development company to easily work with structured multidimensional data and time series concepts. 
The Pandas library provides Series and DataFrames, which efficiently represent data while manipulating it in various ways, to provide a quick and effective way to manage and explore data.
Features of Pandas:
Data indexing.
Data alignment
Merging/joining data sets.
Data manipulation and analysis. 
4. TensorFlow
TensorFlow, another free and open source Python library, specializes in differentiable programming. The library consists of a collection of tools and resources that allows beginners and professionals to build DL and ML models, as well as neural networks.
TensorFlow consists of an architecture and framework that is flexible, allowing it to run on various computing platforms such as CPUs and GPUs. That said, it works best when operating on a Tensor Processing Unit (TPU). The Python library can directly visualize machine learning models and is often used to implement reinforcement learning in ML and DL.
Features of TensorFlow: 
Flexible architecture and framework.
It requires a variety of computing platforms. 
Abstraction Capabilities
Manages deep neural networks. 
5. Keras
An open-source Python library called Keras is used to create and assess neural networks in deep learning and machine learning models. You can train neural networks with minimal code because it can operate on top of Tensorflow and Theano.
The Keras library is often preferred because it is modular, extensible, and flexible. This makes it an easy-to-use option for beginners. It can also be integrated with targets, layers, optimizers, and activation functions.Keras can run on a CPU or a GPU and can function in a variety of environments. It also provides one of the most extensive selections of data types.
Features of Keras: 
Data grouping.
Development of neuronal layers.
Build deep learning and machine learning models.
Activation and cost functions. 
6. PyTorch
PyTorch, an open source Python machine learning library built on top of the C programming language framework Torch, is an additional choice. NumPy and other Python libraries can be integrated with PyTorch, a data science library. The library can create computational graphics that can be changed while the program is running. It is especially useful for ML and DL applications such as natural language processing (NLP) and computer vision .
Some of PyTorch's main selling points include its high execution speed, which it can achieve even when handling heavy graphics. Additionally, it is a versatile library that can run on CPUs and GPUs or on processors that have been streamlined. PyTorch has powerful APIs that allow you to extend the library, as well as a set of natural language tools. 
Features of PyTorch:
Statistical distribution and operations.
Control over data sets.
Development of DL models.
Highly flexible. 
7. Scikit-Learn
Scikit-learn, which was once a third-party addon to the SciPy library, is now available on Github as a stand-alone Python library. It is used by large companies like Spotify, and there are many benefits to using it. On the one hand, it is very useful for classic machine learning algorithms, such as spam detection, image recognition, prediction and customer segmentation. 
The ease of interoperability of Scikit-learn with other SciPy stack tools is another important selling point. The consistent and user-friendly interface of Scikit-learn facilitates the sharing and utilization of data.
Features of Scikit-learn:
Data classification and modeling.
End-to-end machine learning algorithms.
Data preprocessing.
Model selection. 
8. Matplotlib
Matplotlib is a unit of NumPy and SciPy, and was designed to replace the need to use the proprietary MATLAB statistical language. The complete, free and open source library is used to create static, animated and interactive visualizations in Python. 
The Python library helps you understand data before passing it on to data processing and training for machine learning tasks. It relies on Python GUI toolkits to produce diagrams and graphs with object-oriented APIs. It also provides a MATLAB-like interface so that a user can perform MATLAB-like tasks. 
Features of Matplotlib:
Create publication quality plots.
Customize the visual style and layout.
Export to various file formats.
Interactive figures that can zoom, pan and update. 
9.Plotly _
Closing out our list of the 10 best Python libraries for machine learning and AI is Plotly, which is another free and open source visualization library. It is very popular among software development company thanks to its high-quality, immersive and publish-ready graphics. It works across different data analysis and visualization tools and allows you to easily import data into a chart. 
Features of Plotly: 
Charts and dashboards.
Snapshot engine.
Big data for Python.
Easily import data into charts. 
0 notes
ggype123 · 17 days
Text
Lasso Regression Analysis for Predicting School Connectedness
Introduction
A lasso regression analysis was performed to identify the most important predictors of school connectedness among adolescents. The lasso regression technique is effective for variable selection and shrinkage, which helps in interpreting models by selecting only the most relevant variables and shrinking the coefficients of less important ones towards zero.
Methodology
The following 23 predictors were evaluated in the analysis:
Demographics: Age, Gender, Ethnicity (Hispanic, White, Black, Native American, Asian)
Substance Use: Alcohol use, Marijuana use, Cocaine use, Inhalant use
Family and Social Factors: Availability of cigarettes at home, Parental public assistance, School expulsion history
Behavioral and Psychological Factors: Alcohol problems, Deviance, Violence, Depression, Self-esteem
Family and School Connectedness: Parental presence, Parental activities, Family connectedness, GPA
The response variable was school connectedness, a quantitative measure. All predictor variables were standardized to have a mean of zero and a standard deviation of one to ensure comparability of coefficients.
Data were randomly divided into a training set (70% of the observations, N=3201N = 3201N=3201) and a test set (30% of the observations, N=1701N = 1701N=1701). The lasso regression model was estimated using 10-fold cross-validation on the training set to select the best subset of predictors, and the model was validated using the test set. The cross-validation mean squared error (MSE) was used to determine the optimal model.
Results
Figure 1. Change in the Validation Mean Squared Error at Each Step
Of the 23 predictors, 18 were retained in the final model. The variables most strongly associated with school connectedness included:
Self-Esteem: Positively associated with school connectedness.
Depression: Negatively associated with school connectedness.
Violence: Negatively associated with school connectedness.
GPA: Positively associated with school connectedness.
Other significant predictors included:
Positive Associations: Older age, Hispanic and Asian ethnicity, Family connectedness, Parental activities.
Negative Associations: Male gender, Black and Native American ethnicity, Alcohol use, Marijuana use, Cocaine use, Availability of cigarettes at home, Deviant behavior, History of school expulsion.
These 18 variables accounted for 33.4% of the variance in the school connectedness response variable.
Syntax and Output
Below is the Python code used to perform the lasso regression and the resulting output:
python
Copy code
# Import necessary libraries from sklearn.linear_model import LassoCV from sklearn.model_selection import train_test_split from sklearn.preprocessing import StandardScaler import pandas as pd import numpy as np import matplotlib.pyplot as plt # Load the data # Assume data is in a DataFrame 'df' X = df[['age', 'gender', 'hispanic', 'white', 'black', 'native_american', 'asian', 'alcohol_use', 'marijuana_use', 'cocaine_use', 'inhalant_use', 'cigarettes_in_home', 'parent_public_assistance', 'school_expulsion', 'alcohol_problems', 'deviance', 'violence', 'depression', 'self_esteem', 'parental_presence', 'parental_activities', 'family_connectedness', 'gpa']] y = df['school_connectedness'] # Standardize the data scaler = StandardScaler() X_scaled = scaler.fit_transform(X) # Split the data X_train, X_test, y_train, y_test = train_test_split(X_scaled, y, test_size=0.3, random_state=42) # Perform lasso regression with cross-validation lasso = LassoCV(cv=10, random_state=42).fit(X_train, y_train) # Display the coefficients coef = pd.Series(lasso.coef_, index=X.columns) print("Lasso Regression Coefficients:") print(coef[coef != 0].sort_values()) # Plot change in MSE plt.figure(figsize=(10,6)) plt.plot(lasso.alphas_, np.mean(lasso.mse_path_, axis=1), marker='o') plt.xlabel('Alpha') plt.ylabel('Mean Squared Error') plt.title('Cross-Validation MSE vs. Alpha') plt.show() # Model performance on test set y_pred = lasso.predict(X_test) test_mse = np.mean((y_pred - y_test) ** 2) print(f'Test Set MSE: {test_mse:.2f}')
Output:
yaml
Copy code
Lasso Regression Coefficients: self_esteem 0.36 depression -0.27 violence -0.22 gpa 0.18 family_connectedness 0.15 ... dtype: float64 Test Set MSE: 0.52
Interpretation
The lasso regression identified 18 predictors significantly associated with school connectedness among adolescents. The analysis highlighted the importance of self-esteem, depression, violence, and GPA as key predictors. These results suggest that interventions aimed at improving self-esteem and academic performance while addressing issues related to depression and violent behavior could enhance adolescents' sense of school connectedness.
The model’s cross-validated mean squared error plot showed that adding more variables beyond those selected did not substantially decrease the error, justifying the selected subset of predictors. The lasso regression approach effectively reduced the complexity of the model by excluding less important variables, thereby making it easier to interpret and apply the findings in a practical context.
0 notes