xMin establishes the smallest x value, the left end of the x axis.

xMax establishes the largest x value, the right end of the x axis.
This value must be larger than the value entered for Xmin.

xScl defines the spacing between tic marks along the x axis.
To turn off the marks, set Xscl to 0.

yMin establishes the smallest y value, the bottom of the y axis.

yMax establishes the largest y value, the top of the y axis.
This value must be larger than the value entered for Ymin.

yScl defines the spacing between tic marks along the y axis.
To turn off the marks, set Yscl to 0.

xRes establishes the number of values of x calculated and graphed.
xRes = 1 uses every pixel, while xRes = 8 uses every eighth pixel.

To change a setting, select that value using the cursor keys and type the desired value.