simtb_figdimension

   simtb_figdimension() - Computes position of figure given desired aspect ratio and scale

   Usage:
    >> RECT = simtb_figdimension(aspectratio, scale, alignment);

   INPUTS: (OPTIONAL)
   aspectratio   = aspect ratio is width/height of the desired figure
   scale         = multiplicative scale, 1 leaves the same size
   alignment     = horizontal placement, vertical placement
                       'cm' = center middle
                       'lt' = left top
                       'rb' = left bottom

   OUTPUTS:
   RECT          = figure position used as figure('Position', RECT)

   see also: simtb_figure_params(), simtb_showSM()