findPngDevice.Device: Searches for a working PNG device
In HenrikBengtsson/R.graphics: [R] Class Library - Graphics classes

Description Usage Arguments Value Author(s) See Also Examples

Searches for a working PNG device.

On Unix, the png device requires that X11 is available, which it is not when running batch scripts or running R remotely.

This method tries to create a simple png file first using the png() device, and if that is not working it tries the bitmap() device, which does not require X11 etc, because it utilizes Ghostscript.

1	Device$findPngDevice(...)

...

Not used.

Returns the png function, the bitmap function, or NULL.

Henrik Bengtsson (http://www.braju.com/R/)

For more information see Device.

   fcn <- Device$findPngDevice();
   if (identical(fcn, png)) {
     cat("PNG device found: png()");
   } else if (identical(fcn, bitmap)) {
     cat("PNG device found: bitmap()");
   } else {
     cat("PNG device not found.");
   }