animation (version 2.4.1)

saveGIF: 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 = "convert",  cmd.fun, clean = TRUE, ...)
saveMovie(expr, movie.name = "animation.gif", img.name = "Rplot", convert = "convert",  cmd.fun, clean = TRUE, ...)

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

...

other arguments passed to ani.options, e.g. ani.height and ani.width, ...

Value

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

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!

References

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

See Also

Other utilities: im.convert, saveHTML, saveLatex, saveSWF, saveVideo

Examples

## make sure ImageMagick has been installed in your system
saveGIF({
    for (i in 1:10) plot(runif(10), ylim = 0:1)
})

## if the above conversion was successful, the option 'convert' should not be NULL
## under Windows
ani.options("convert")
## like 'C:/Software/LyX/etc/ImageMagick/convert.exe'

saveGIF({
    brownian.motion(pch = 21, cex = 5, col = "red", bg = "yellow")
}, movie.name = "brownian_motion.gif", interval = 0.1, nmax = 30, ani.width = 600, 
    ani.height = 600)

## non-constant intervals between image frames
saveGIF({
    brownian.motion(pch = 21, cex = 5, col = "red", bg = "yellow")
}, movie.name = "brownian_motion2.gif", interval = runif(30, 0.01, 1), nmax = 30)