(PECL ps >= 1.1.0)
ps_scale — Sets scaling factor
$psdoc
   , float $x
   , float $y
   ) : boolSets horizontal and vertical scaling of the coordinate system.
psdocResource identifier of the postscript file as returned by ps_new().
xScaling factor in horizontal direction.
yScaling factor in vertical direction.
   成功时返回 TRUE, 或者在失败时返回 FALSE。