dergachev

OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

tskaggs

Convert MOV to GIF using FFmpeg and ImageMagick

I tried a few different techniques to make a GIF via command-line and the following gives me the best control of quality and size. Once you're all setup, you'll be pumping out GIFs in no time!

Preparation

Install FFmpeg

• $ brew install ffmpeg [all your options]
  • Example: $ brew install ffmpeg --with-fdk-aac --with-ffplay --with-freetype --with-frei0r --with-libass --with-libvo-aacenc --with-libvorbis --with-libvpx --with-opencore-amr --with-openjpeg --with-opus --with-rtmpdump --with-schroedinger --with-speex --with-theora --with-tools

Install ImageMagick

ndarville

[Isolating Differences Between Files][paper]

Advantage over Other Algorithms

The diff output is more specific:

[I]f a whole block of text is moved, then all of it, rather than just the beginning and end, is detected as changed.

>The algorithm described here avoids these difficulties. It detects differences that correspond very closely to our intuitive notion of difference.

dpseidel

Default ggplot2 aesthetics by geom.

geom	alpha	angle	colour	family	fill	fontface	height	hjust	lineheight	linetype	shape	size	stroke	vjust	weight	width	xmax	xmin	ymax	ymin
GeomAbline	NA		black							1		0.5
GeomAnnotationMap	NA		NA		grey20					1		0.5
GeomArea	NA		NA		grey20					1		0.5
GeomBar	NA		NA		grey35					1		0.

baptiste

library(ggplot2)
set.seed(1221)

dat <- data.frame(x=rnorm(100), y=rnorm(100), type=rep(1:2, each=50))
p <- ggplot(dat) + geom_point(aes(x, y)) +
  facet_wrap(~type) + coord_fixed() +
  theme(plot.background = element_rect(fill='red'))

# inspired by
# egg::set_panel_size

TysonStanley

library(bench)      # assess speed and memory
library(data.table) # data.table for all of its stuff
library(dplyr)      # compare it to data.table
library(profmem)    # assess the process of R functions

set.seed(84322)

# Example Data
d <- data.table(
  grp = sample(c(1,2), size = 1e6, replace = TRUE) %>% factor,

jhollist

library(USAboundaries)
library(sf)
library(dplyr)
library(elevatr)
library(raster)

# Get map of lower 48 states
usa_l48 <- us_boundaries() %>%
  filter(state_abbr != "HI" & 
           state_abbr != "AK" &

eliocamp

library(data.table)
library(ggplot2)
data(volcano)
volcano <- as.data.table(melt(volcano, varnames = c("x", "y"),
                              value.name = "h"))


volcano[, c("dx", "dy") := metR::Derivate(h ~ x + y)]  # from my package. It calculates directional derivatives. 
volcano[, angle := atan2(-dy, -dx)]