R: Convert images to a single animation file (typically GIF)...

saveGIF {animation}

R Documentation

Convert images to a single animation file (typically GIF) using ImageMagick or GraphicsMagick

Description

This function opens a graphical device (specified in ani.options('ani.dev')) first to generate a sequence of images based on expr, then makes use of the command convert in ‘ImageMagick’ to convert these images to a single animated movie (as a GIF or MPG file). An alternative software package is GraphicsMagick (use convert = 'gm convert'), which is smaller than ImageMagick.

Usage

saveGIF(
  expr,
  movie.name = "animation.gif",
  img.name = "Rplot",
  convert = "magick",
  cmd.fun,
  clean = TRUE,
  extra.opts = "",
  ...
)

saveMovie(
  expr,
  movie.name = "animation.gif",
  img.name = "Rplot",
  convert = "magick",
  cmd.fun,
  clean = TRUE,
  extra.opts = "",
  ...
)

Arguments

`expr`	an expression to generate animations; use either the animation functions (e.g. `brownian.motion()`) in this package or a custom expression (e.g. `for(i in 1:10) plot(runif(10), ylim = 0:1)`).
`movie.name`	file name of the movie (with the extension)
`img.name`	file name of the sequence of images (‘pure’ name; without any format or extension)
`convert`	the command to convert images (default to be `convert` (i.e. use ImageMagick), but might be `imconvert` under some Windows platforms); can be `gm convert` in order to use GraphicsMagick; see the 'Note' section for details
`cmd.fun`	a function to invoke the OS command; by default `system`
`clean`	whether to delete the individual image frames
`extra.opts`	additional options passed to `im.convert`
`...`	other arguments passed to `ani.options`, e.g. `ani.height` and `ani.width`, ...

Details

This function calls im.convert (or gm.convert, depending on the argument convert) to convert images to a single animation.

The advantage of this function is that it can create a single movie file, however, there are two problems too: (1) we need a special (free) software ImageMagick or GraphicsMagick; (2) the speed of the animation will be beyond our control, as the interval option is fixed. Other approaches in this package may have greater flexibilities, e.g. the HTML approach (see saveHTML).

See ani.options for the options that may affect the output, e.g. the graphics device (including the height/width specifications), the file extension of image frames, and the time interval between image frames, etc. Note that ani.options('interval') can be a numeric vector!

Value

The command for the conversion (see im.convert).

Note

See im.convert for details on the configuration of ImageMagick (typically for Windows users) or GraphicsMagick.

It is recommended to use ani.pause() to pause between animation frames in expr, because this function will only pause when called in a non-interactive graphics device, which can save a lot of time. See the demo 'Xmas2' for example (demo('Xmas2', package = 'animation')).

saveGIF has an alias saveMovie (i.e. they are identical); the latter name is for compatibility to older versions of this package (< 2.0-2). It is recommended to use saveGIF to avoid confusions between saveMovie and saveVideo.

Author(s)

Yihui Xie

References

Examples at https://yihui.org/animation/example/savegif/

ImageMagick: http://www.imagemagick.org/script/convert.php;

GraphicsMagick: http://www.graphicsmagick.org