Gridstyle Keyword
Used With Routines:  AXIS,  BAR3D,  BOXPLOT,  CONTOUR,  CONTOURFS,  CONTOUR2,  OPLOT,  PLOTSHADE_SURF,  SURFACE
Corresponding System Variable:  !P.Gridstyle
Lets you change the linestyle of tick intervals.
The default is a solid line. Other linestyle choices and their index values are listed in Table 21-1: Available Linestyles.
One possible use for this keyword is to create an evenly spaced grid consisting of dashed lines across your plot region. To do this, first set the Ticklen keyword to 0.5. This ensures that the dashed tick style will appear correctly on your plot. Then set the Gridstyle keyword to the style you want to use. For example:
PLOT, mydata, Ticklen = 0.5, Gridstyle = 2
produces a plot with a dashed grid across the entire plot region.
See also the PV‑WAVE User’s Guide.