&GSIZE
Controls the spacing between grid points. If reading, it returns the X-spacing value for rectangular grids. If writing, both the X and Y-spacing values for rectangular grids are assigned the specified value.
NOTE: GRIP, beginning with Version 6.0, supports several GPAs which
control grid size parameters for both rectangular and polar grids. These GPAs
are described on the following pages. The &GSIZE GPA is still valid;
however, you are encouraged to use the new GPAs.
Read/Write - Number - Greater Than Zero