#coalg

[pepperyaura]

making art blog

i think its best if i make a seprate blog to post my renders too, so am making a new one! its going to have all my renders, art , stories(if i make them) and animations in one easy assecisble place

please go seeeee it reallyl coalg :3 https://bsky.app/profile/pepperyaura.bsky.social also bluesky account

[favorite-fighting-frenchman]

don’t forget to vote in the theatre fan choice awards!

[seethreepio]

Finally get to see Children of a Lesser God! Congrats to this fabulous cast! #startlistening #childrenofalessergod #miriamseesaplay (at Studio 54 Theatre)

[beautyinsteadofashes]

@fancynewaddress:  fancynewaddress replied to your post “i haven’t even seen them yet  but i feel like Children of a Lesser God...”

With you on Marvin's Room, actually. I haven't seen CoaLG except for the mixed word-of-mouth though.

I haven’t seen either (except the Marvin’s film apparently CoaLG is a film too) but the trailer for CoaLG looks amazing and I trust Josh and Treshelle’s taste in projects. 

[snak]

Calculating fibonacci numbers using recursion schemes

After reading the good articles about recursion scheme by Patrick Thomson, I tried the example in Recursion Schemes, Part IV: Time is of the Essence to calculate fibonacci numbers using histomorphism.

First, let's define histo function. I just took these definitions from those articles.

{-# LANGUAGE DeriveFunctor, StandaloneDeriving, UndecidableInstances #-} import Control.Arrow ((>>>), (<<<), (&&&)) newtype Term f = In { out :: f (Term f) } deriving instance Show (f (Term f)) => Show (Term f) type Coalgebra f a = a -> f a ana :: (Functor f) => Coalgebra f a -> a -> Term f ana coalg = In <<< fmap (ana coalg) <<< coalg data Attr f a = Attr { attribute :: a , hole :: f (Attr f a) } type CVAlgebra f a = f (Attr f a) -> a histo :: Functor f => CVAlgebra f a -> Term f -> a histo h = worker >>> attribute where worker = out >>> fmap worker >>> (h &&& id) >>> uncurry Attr

Now, you need a number type defined using recursions.

data NatF a = ZeroF | SuccF a deriving (Show, Functor) type Nat = Term NatF

You can generate a number of Nat from an ordinal number by using ana.

nat :: (Eq n, Num n) => n -> Nat nat n = ana build n where build 0 = ZeroF build n = SuccF (n - 1)

Then, what you need to do is to write a function that calculates a fibonacci number from NatF (Attr NatF a).

fibF :: Num n => NatF (Attr NatF n) -> n fibF ZeroF = 0 fibF (SuccF (Attr a ZeroF)) = 1 fibF (SuccF (Attr a (SuccF (Attr b _)))) = a + b

As you can see, you pick the previous fibonacci number directly and pick the previous previous fibonacci number from the history in the last pattern.

You can now calculate a fibonacci number by passing fibF to histo.

fib :: (Eq n, Num n, Num m) => n -> m fib n = histo fibF $ nat n

When you compare this fib with this naive implementation (fib'), you'll find that fib runs significantly faster than fib' because it caches intermediate fibonacci numbers.

fib' :: (Eq n, Num n) => n -> n fib' 0 = 0 fib' 1 = 1 fib' n = fib' (n - 1) + fib' (n - 2)

By the way, you don't need to write most of the code above when you use recursion-schemes. As described in Recursion Schemes, Part 4½: Better Living Through Base Functors, it provides a base functor for GHC.Natural.Natural (it's Maybe because our NatF is isomorphic to Maybe), and lifts Natural to Maybe automatically. Also it uses Control.Comonad.Cofree instead of our Attr.

So what you need to do is just write fibF for it.

{-# LANGUAGE TypeApplications #-} import Control.Comonad.Cofree (Cofree((:<))) import Data.Functor.Foldable (Base, histo) import GHC.Natural (Natural) fibF :: Num n => (Base Natural) (Cofree (Base Natural) n) -> n fibF Nothing = 0 fibF (Just (a :< Nothing)) = 1 fibF (Just (a :< Just (b :< _))) = a + b fib :: (Integral n, Num m) => n -> m fib n = histo fibF $ fromIntegral @_ @Natural n

[angelxinxdisguise-blog]

¿Por qué Biu?

El nombre Biu salio de unos dibujos twincest que hace un chica en deviantart, simplemente me pareció divertido usar ese nombre del fandom "twincest" en un fic billdrej.

Y en el fic, pues, este amiguito lindo y hermoso se llama Bill...

Recordemos que Rick a Andrej le dio un animalito de estos y Andrej ya sabia de la existencia de estos peluches, pues, también sabia que había uno llamado Bill, y que era este cerdito, así que al escuchar el nombre Bill y ver el septum del cantante, el piensa en cerditos, mas específicamente en este. Y pues, el nombre biu suena como un lindo nombre para un cerdito y es un lindo y tierno apodo para un lindo y tierno chico como Bill.

[angelxinxdisguise-blog]

Capitulos 15-21 

[angelxinxdisguise-blog]

Bill and Andrej's theme song <3

[angelxinxdisguise-blog]

Trailer de chronicles of a love game hecho por billakomm/billapejic