niw

/*
 * A simple libpng example program
 * http://zarb.org/~gc/html/libpng.html
 *
 * Modified by Yoshimasa Niwa to make it much simpler
 * and support all defined color_type.
 *
 * To build, use the next instruction on OS X.
 * $ brew install libpng
 * $ clang -lz -lpng16 libpng_test.c

drawveloper

This can reduce files to ~15% of their size (2.3M to 345K, in one case) with no obvious degradation of quality.

ghostscript -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/printer -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

Other options for PDFSETTINGS:

• /screen selects low-resolution output similar to the Acrobat Distiller "Screen Optimized" setting.
• /ebook selects medium-resolution output similar to the Acrobat Distiller "eBook" setting.
• /printer selects output similar to the Acrobat Distiller "Print Optimized" setting.
• /prepress selects output similar to Acrobat Distiller "Prepress Optimized" setting.

timvisee

Falsehoods programmers believe about time

This is a compiled list of falsehoods programmers tend to believe about working with time.

Don't re-invent a date time library yourself. If you think you understand everything about time, you're probably doing it wrong.

Falsehoods

• There are always 24 hours in a day.
• February is always 28 days long.
• Any 24-hour period will always begin and end in the same day (or week, or month).

alex-hhh

#lang racket
;; Updated plot library required, https://github.com/alex-hhh/plot/tree/ah/interactive-overlays
(require plot pict)

;; Helper function to add a pict as a plot overlay -- don't want to add "pict"
;; as a dependency to the "plot" package
(define (add-pict-overlay plot-snip x y pict)
  (send plot-snip add-general-overlay x y
        (lambda (dc x y) (draw-pict pict dc x y))
        (pict-width pict)

AndiH

LeifAndersen

#lang scratch

(require compiler/zo-structs
         (for-syntax compiler/zo-structs
                     racket/struct-info))

(begin-for-syntax
  (define-values (exports expsyn)
    (module->exports 'compiler/zo-structs))
  (define struct-types

alex-hhh

#lang racket
(require racket/draw
         racket/promise
         plot
         plot/utils
         pict)

;; These color maps correspond to the Matplotlib 3.0.3 qualitative color maps
;; with the same names.  See
;; https://matplotlib.org/examples/color/colormaps_reference.html

LiberalArtist

brianhempel

#!/usr/bin/env ruby

HELP_STR = "Usage: $ remove_rightslink_images file1.pdf file2.pdf"

begin
  require 'hexapdf' # HexaPDF is AGPL licensed according to https://hexapdf.gettalong.org/
rescue LoadError
  if system("gem install --no-doc hexapdf")
    Gem.clear_paths
    require "hexapdf"

graninas

At the beginning of 2030, I found this essay in my archives. From what I know today, I think it was very insightful at the moment of writing. And I feel it should be published because it can teach us, Rust developers, how to prevent that sad story from happening again.

---

What killed Haskell, could kill Rust, too

What killed Haskell, could kill Rust, too. Why would I even mention Haskell in this context? Well, Haskell and Rust are deeply related. Not because Rust is Haskell without HKTs. (Some of you know what that means, and the rest of you will wonder for a very long time). Much of the style of Rust is similar in many ways to the style of Haskell. In some sense Rust is a reincarnation of Haskell, with a little bit of C-ish like syntax, a very small amount.

Is Haskell dead?