htbPlotAnim: Creator for animated movie graphics

In keimochizuki/htb: Read and Analyze Neural Activities Acquired by TEMPO System

Creator for animated movie graphics

Description

Creates a movie clip from sequential graphical outputs.

Usage

htbPlotAnim(
  filename,
  width,
  height,
  expr,
  type = c("mp4", "gif"),
  img = c("png", "jpg"),
  converter = NULL,
  digit = 5,
  kbps = "300k",
  fps = 10,
  recursive = TRUE,
  scale = 100,
  transparent = "",
  verbose = TRUE
)

Arguments

filename	A string. The name of the created movie file. The extension (.eps) can be omitted if valid file type is designamted by type argument.
width	A numeric. The width of the device in pixels.
height	A numeric. The height of the device in pixels.
expr	An expression. R codes to plot a set of static images that are then converted in a movie file. Use braces (curly bracket) to enclose multiple lines of code without bothersome semicolons between commands.
type	A string. The type of the animated output. Either mp4 or gif is supported. (Support for swf is no more available due to the abandonment of Adobe Flash.) If appropriate extension is provided as filename argument, corresponding type is automatically selected.
img	A string. The name of the output device for plotting. Either png (suitable for graphs) or jpg (suitable for picture-like images) is supported.
converter	A string. The name of the command to compile static images into a movie. Either ffmpeg (for mp4 output) or convert (for animated gif output) is automatically selected. Therefore, you do not normally need to explicitly designate this argument. In case your terminal does not have an access to neither of these commands, you can designate a full path to the corresponding executable file as converter, which is then used during system calls in htbPlotAnim().
digit	An integer. The number of digits reserved for plotting static frames. Default value 5 will be normally enough since this means you can use up to 99999 frames, i.e., almost 60-min movie in 30 fps.
kbps	An integer. An approximate target bit rate for mp4 output passed to ffmpeg. Ignored when using convert for gif output.
fps	An integer. The frame rate of the movie.
recursive	A logical. Whether to make the animated gif file to be recursively looped or not. Ignored when using ffmpeg for mp4 output.
scale	A numeric. Rescaling parameter used during creation of the movie from static images. Normally use 100 (default) if you have already sellected a desired size of the movie by width and height. In some cases, this argument might be useful if you wish to draw source images in high resolution but only need coarse movie (scale < 100 with large width and height). Alternatively, you can also draw coarse images in low resolution but still make the movie output to be geometrically larger in size (scale > 100 with small width and height).
transparent	A string. The color recognized as a background and made to be transparent in animated gif output. If not set, all the images are used without transparency. Ignored when using ffmpeg for mp4 output.
verbose	A logical. Whether to print detailed output from the converting command into R's terminal.

Details

When analyzing the data, there are often cases you want to visualize your result in animated movie clips rather than static graphics like eps or png. htbPlotAnim() provides an easy way to such dynamic graphical outputs. Since R intrinsically does not have built-in dynamic graphics, this function achieves it by virtue of external software such as ffmpeg or convert (ImageMagic). By just designing the size of the output along with a set of R codes to plot multiple sequential static images, htbPlotAnim() puts out those images as temporal files and concatenates them into a movie clip. Static images are then automatically removed, thus no garbage files are left behind.

If corresponding terminal command (ffmpeg for mp4 and convert for gif) is not available, htbPlotAnim() cannot compile a movie and prints an error. In such a case, please install the required software and make sure it is executable. (Management of environmental variable may be needed for Windows users.) Alternatively, you can explicitly designate a full path to the converting command by converter argument. Be careful, however, because consistency between output file type and the converting command is not verified in this case.

Examples

## Not run: 
n <- 150
w0 <- cumsum(rnorm(n, mean = 0))
w1 <- cumsum(rnorm(n, mean = 0.2))
htbPlotAnim("randomwalk.mp4", 320, 240, {
  par(mar = c(3, 3, 1, 1), las = 1)
  for (i in 1:n) {
    j <- 1:i
    blankplot(xlim = c(0, i), ylim = range(c(w0[j], w1[j])))
    lines(j, w0[j], lty = "22")
    lines(j, w1[j], lwd = 2)
  }
}, fps = 15)

## End(Not run)

keimochizuki/htb documentation built on June 9, 2025, 10:03 p.m.