These values define the tickmarks on both axes. Numerically these numbers represent x-axis major tickmarks, x-axis minor tickmarks, y-axis major tickmarks, and y-axis minor tickmarks, respectively. Labels are placed at major tickmarks. When gridlines are drawn, they are drawn through all the tickmarks.
Example setting tickmarks
Therefore, setting the axes to -20, 20,-10, 10 and tickmarks to 4,5,4,5 would result in the following:
x-axis:
The x-range is from -20 to 20;
It is divided into four equally-spaced intervals, resulting in major tickmarks and labels at -20, -10, 0, 10, and 20; and
Each interval is further divided into five equally-spaced subintervals, resulting in a minor tickmark every two units.
y-axis:
The y-range is from -10 to 10;
It is divided into four equally-spaced intervals, resulting in major tickmarks and labels at -10, -5, 0, 5, and 10; and
Each interval is further divided into five equally-spaced subintervals, resulting in a minor tickmark every (one) unit.