Open an HTML canvas graphics device

Opens a graphics device that records subsequent plotting commands as JavaScript CanvasRenderingContext2D calls, writing them to a self-contained HTML file as they happen. Each new page of plotting (for instance, each top-level graphics::plot() call, or each panel of a par(mfrow = ...) layout) starts a fresh <canvas> element in the file, so a device left open across several plots produces several canvases stacked down the page. Close the device with grDevices::dev.off() to finish writing the file.

Usage

cnvs(
  file = "cnvs.html",
  width = 480,
  height = 480,
  pointsize = 12,
  bg = "white"
)

Arguments

file

Path of the HTML file to create.

width, height

Device size, in pixels (used directly as the width/height attributes of the <canvas> element).

pointsize

The default font pointsize, in big points (1/72 inch), following the same convention as grDevices::pdf() and friends.

bg

Default background colour, as a colour name or other value accepted by grDevices::col2rgb().

Value

Invisibly, NULL. Called for the side effect of opening a new graphics device.

Examples

f <- tempfile(fileext = ".html")
cnvs(f)
plot(1:10, main = "cnvs demo")
dev.off()
#> agg_record_18f535ffe68 
#>                      2 
# browseURL(f) # to view the result in a browser