The functions in this section control the X axis and Y axis tick marks. You can set the tick interval or control the number of ticks, suppress the first or last tick on an axis, and control the tick size.

Left to its own, PHPlot will determine tick values for X and Y axes, but it currently isn't too smart about choosing values and you may not be happy with the results. You can use the functions in this section to set the desired tick interval or number of ticks, but you will most likely also have to call SetPlotAreaWorld to set the X and/or Y data range limits. Otherwise, you get the tick intervals you want, but the actual values will depend on a somewhat arbitrary base value.