### 4.4.1. Plot of 2D Functions

Up to six functions can be plotted simultaneously. Using the Edit → Functions dialogue, you can either type the formula directly into the Function box or double-click on it to open the Formula Editor. Functions can be plotted in any interval. However, neither X nor Y-axis values will be automatically scaled. The values suggested by the program on entry have nothing to do with the functions supplied by the user. The X and Y interval values may be edited to regulate the frequency of ticks and numbers displayed on X and Y axes.

Plot Frequency values range
from 1 to 10. The measure of frequency is in terms of the number of pixels at
which the function will be evaluated. For instance, if the frequency is 10,
then functions are evaluated at every 10^{th} pixel. If the field
displays 1 then functions will be evaluated at each and every pixel. Therefore,
it is advisable to plot functions first at the lowest resolution (i.e. at a Plot Frequency of 10) in order to get some idea of their
behaviour in the specified interval. Although a Plot
Frequency of 1 will provide the highest possible resolution, the
plotting speed may be low when complex functions are evaluated.