This operator specifies explicity the current transformation matrix. The argument elements a b c d make up the elements of a 2 by 2 matrix. This is the linear transformation part of the affine transformation. The translation is specified by tx and ty for the x and y directions respectively.
This operator pushes saves a copy of the current graphics state The graphics state consists of (among other things):
Sets the current graphics state to the last graphics state saved with gsave.
This operator rotates the current frame of reference by angle degrees counter-clockwise.
This operator scales the current frame of reference by a factor of x-scale in the x direction and y-scale in the y direction.
This operator translates the current frame of reference by x-shift in the x direction and y-shift in the y direction.