Export graphics to PNG.
xs2png(win_num, file_name)
xs2png(fig, file_name)
:win_num integer, id of the figure to export. : :fig handle of the figure to export. : :file_name string, name of the exported file. :
xs2png exports the display of a graphic window into a PNG file.
`scf`_(0)
`plot2d`_()
//PNG export
xs2png(0,'foo.png');
xs2png(`gcf`_(),'foo.png');