@racketlang
I love these Easter eggs in #DrRacket

Happy King Kamehameha I Day!
#DrRacket #easteregg

Did you know Racket runs on the Raspberry Pi?
IDE, compiler, libraries and documentation included for stand alone use.
32-bit ARMv6 VFP (built on Raspbian) at https://users.cs.utah.edu/plt/snapshots/current/installers/racket-8.17.0.2-arm-linux-cs.sh via https://snapshot.racket-lang.org
@raspberrypi.com @Raspberry_Pi #raspberrypi #racketlisp #lisp #drracket

Hubo un tiempo lejano donde me sentí tentado de aprender algo de programación con el IDE #DrRacket. El lenguaje @racketlang. ¿Qué os parece la idea?

Finally I'm starting to get a bit more comfortable with all those parentheses and I'm starting to make my own changes in the code without #DrRacket complaining at every single step 💪

Racket - the Language-Oriented Programming Language - version 8.15 is now available from https://download.racket-lang.org

See https://blog.racket-lang.org/2024/11/racket-v8-15.html for the release announcement and highlights. #DrRacket #Racket #RacketLanguage

I've been making progress with learning #Racket and #Scheme. I did add the csv-reader package to #DrRacket to help me along.

One of the report files has well over 100 rows. So it takes 1024MB of memory just to read it in. I haven't really begun to use #lambda on these lists yet. I'm interested to see how the performance compares to my #python scripts.

I got inspired to study #Scheme and I installed #drracket. Over 20 years ago I worked with #DSSSL, a subset of Scheme.

My goal is to write some scripts to parse large CSV files. I've used #Python for similar tasks.

#lang racket
(require plot)
(require math/distributions)
;; R to Racket
;; ; Ztable, ZScore ??
;; ; (curve(dnorm(x, mean=0, sd=1), from=-4 to=4)
;; ; abline(v=qnorm(p=0.025, mean=0, sd=1)) ;; a=0.05(5%)とした場合
;; ; abline(v=qnorm(p=0.975, mean=0, sd=1))

(define n-d-0-1 (normal-dist 0 1))
(cdf n-d-0-1 0.025) ;; https://docs.racket-lang.org/math/dist_dist-objects.html
;; ; 0.509972518195238
(inv-cdf n-d-0-1 0.025) ;; https://docs.racket-lang.org/math/dist_dist-objects.html
;; ; -1.9599639845400538
(inv-cdf n-d-0-1 0.975) ;; 1.9599639845400536
#;(define (n-d-0-1-pdf x)
  ((distribution-pdf n-d-0-1) x))
;; (n-d-0-1-pdf -4) ;; 0.00013383022576488534
;; (n-d-0-1-pdf 4)  ;; 0.00013383022576488534
#;(plot (function n-d-0-1-pdf)
      #:x-min -4
      #:x-max 4)
(define cdf-inv-0025 (inv-cdf (normal-dist 0 1) 0.025))
(define cdf-inv-00975 (inv-cdf (normal-dist 0 1) 0.975))

(plot (list
      (function (distribution-pdf (normal-dist 0 1)))
      (lines (list (vector cdf-inv-0025 0) (vector cdf-inv-0025 .4)))
      (lines (list (vector cdf-inv-00975 0) (vector cdf-inv-00975 .4)))
      ); end list of plot functions
      #:x-min -4 #:x-max 4
      #:out-file "norm-dist-inv-cdf-1.png")

;; ; https://www.medi-08-data-06.work/entry/2018/12/18/232204
;; ; https://r-coder.com/normal-distribution-r/
;; ; https://www.statology.org/dnorm-pnorm-rnorm-qnorm-in-r/
;; ; cdf, inverse-cdf https://docs.racket-lang.org/math/dist_dist-objects.html

;; (require math/statistics) ;; quantile
;;(quantile 0.025 < n-d-0-1) ;; no good, how to get xs from normal-dist??

Was soll das für function composition sein, wenn nicht mal

| (compose flip flip) == identity

stimmt und mir dafür Arity-Error entgegen wirft.

Kurz in #ghci geprüft, und glücklich geworden.

#Racket #DrRacket #Scheme #Haskell

I had been thinking it would be great to see two different views of the unit circle while floundering around making circular meme-like images. So it is great to find this while searching for general Racket Plot pages:
https://alex-hhh.github.io/2021/01/plot-animations.html
#AlexHarsányi #AlexHarsanyi #RacketPlot #SineFunction #PlotAnimation #RacketPlotAnimation #DrRacket

@fiskfan1999 Although I don't enjoy using #DrRacket , there are actually good reasons why you might want to use it when learning Racket, or indeed when developing languages in #Racket - it does things "out of the box" that are difficult or complex to achieve without it.

Learning Vim or Emacs might seem valuable, but might detract from what you're supposed to be focussing on. The goal of CompSci is not to teach you to edit text efficiently, after all.

高橋メソッド と もんたメソッド ^1 は #DrRacket と #Racket, #RacketSlideshow でするのが楽しいそうです。 友達が中学校を卒業した人達に挨拶するとき、 素朴なメッソッドでスライドを見せたいらしい。#Slideshow ^2 ですぐ#高橋メソッド できた、 簡単な #もんたメソッド もDRY理念を虫したら簡単にできそうけどplay-n ^3使った関数を作ったら繰り返しのない、ちょっと派手なスライドできそう。時間を作って、集中力の訓練としてやってみようかな。
ところで、#みのもんた は10何年前テレビで見たときに本能的にきらいだった。 最近「#ウンコな議論」を読みだしたら、その気持を説明できるようになりつつある。 ビジネスCMの影響が強すぎる社会になると、 ありそうな顔だけで、 見せかけのことで通せる感じ。 似ったような居眠り権力者、化石頭、があちこち決定権を握てしまっているじゃないかな？
^1 https://note.com/yumi_nomo/n/ndde9a3ee5cd0
^2 https://docs.racket-lang.org/slideshow/Creating_Slide_Presentations.html#%28part._.Slide_.Basics%29
^3 https://docs.racket-lang.org/slideshow/play.html#%28def._%28%28lib._slideshow%2Fplay..rkt%29._play-n%29%29

> #ShriramKrishnamurthi some years ago, in talking up the intro Scheme class they'd put together at Rice.. said they had other departments wanting to send their students over for the Scheme intro, to learn how to think. Which had me.. trying to remember where that quote came from about 'computer science isn't a science and its significance has little to do with computers'.
#HTDP #RacketLang #DrRacket

Evenutally I'll find the data and gnuplot code used to generate this visualization. Once I find the directory I'll have to re-do it with Racket's plot so people can adjust the view in #DrRacket. #DataVisualization with #concrete or #cement figures for #Japan from #DavidKerr's #DogsAndDemons.

> .. everyone can experience the satisfaction that comes with creative design.. program design—but not #programming—deserves the same role in a #LiberalArts education as mathematics and language skills.
> A student of design who never touches a program again will still pick up universally useful problem-solving skills, experience a deeply creative activity, and learn to appreciate a new form of aesthetic.
https://htdp.org/2022-2-9/Book/part_preface.html
#DrRacket #Racket #GeneralEducation

> This book is the first book on #programming as the core subject of a #LiberalArts #education. Its main focus is the design process that leads from problem statements to well-organized solutions.. Our desire to focus on the design process requires two radical innovations for introductory courses. The first innovation is a set of explicit design guidelines.. The second innovation is a radically new #programmingEnvironment..
https://htdp.org/2003-09-26/Book/curriculum-Z-H-2.html
#DrRacket #Racket #GeneralEducation #HTDP

launch #drracket today if you have #racket installed :D

Hey, does anyone know how to customize indent in #DrRacket?

I'm doing my code like so:

(define (foo)
(stuff)
(more stuff)
)

With actual tabs, the /proper/ way. But DrRacket seems to have /zero/ settings for this. And I'm worried it'd try to force hanging indent on me as well.