With no arguments, the bounding box (in pixels) of the grid is returned. The return value consists of 4 integers. The first two are the pixel offset from the master window (x then y) of the top-left corner of the grid, and the second two integers are the width and height of the grid, also in pixels. If a single column and row is specified on the command line, then the bounding box for that cell is returned, where the top left cell is numbered from zero. If both column and row arguments are specified, then the bounding box spanning the rows and columns indicated is returned.