The N is an integer value in the range 1-7. Each register
index can store both a physical and electrical grid specification.
The specifications define the contents of the grid registers,
available in the Grid Setup panel and elsewhere.
The spec string has the form:
snapspace snapval linestyle [xsize]
[-a axes] [-d dsp]
[-t ontop] [-m cmult]
The first three tokens are mandatory, and must appear in the order
shown.
- snapspace (real number)
The spacing between snap points, in microns.
- snapval (integer, -10 through 10 excluding 0)
If the value is positive, it sets the number of snap points per fine
grid line. For example, a value of 3 would indicate that a fine grid
line is drawn at every third snap point. If negative, this sets the
number of fine grid lines per snap interval. In this case, a value of
three indicates that fine grid lines appear at snap points and at the
1/3 and 2/3 proportional distances within the snap interval.
- linestyle (integer)
This is the line style code. The value is 0 for a dot grid, otherwise
the bit pattern represents the line dashes, as for the GridStyle
keyword.
The remaining tokens are optional, and can follow the first three in
any order.
- xsize (integer 0-6)
If the linestyle code is 0 (for a dot grid), then a fourth
number can appear. This is an integer 0-6 which indicates the number
of pixels in the four orthogonal directions to extend the dot into a
cross.
- -a axes (integer 0-2)
This sets the axes presentation mode in physical mode. If 0, axes are
shown and the origin decorated. If 1, plain axes are shown, and if 2,
axes aren't shown.
- -d dsp (boolean)
This sets whether the grid is displayed or not. The dsp token
can be about any alphanumeric token that by convention indicates true
or false.
- -t ontop (boolean)
This sets whether the grid is displayed after all geometry (``on
top'') or before geometry. The ontop token can be about any
alphanumeric token that by convention indicates true or false.
- -m cmult (integer 1-50)
This sets the number of fine grid lines per coarse grid line.
For backward compatibility, ``GridReg'' is accepted as ``PhysGridReg''.
