The aspect ratio is defined by the ratio of the number of pixels
for one data unit on the y axis and the number of pixels for one data unit
on the x axes.
Usage
l_setAspect(widget, aspect, x, y)
Arguments
widget
widget path as a string or as an object handle
aspect
aspect ratio, optional, if omitted then the x and
y arguments have to be specified.
x
optional, if the aspect argument is missing then x and
y can be specified and the aspect ratio is calculted usding
y/x.