On the right-hand side of the dialog box, there is a picture illustrating the chosen function. When you change the function by using the 窶廡unction窶 popup menu, the picture changes accordingly.
The purpose of this picture is to assist you in choosing the right function. Notice also that the picture contains a brief explanation of the parameters. Since the functions interpret the parameters differently, it is important to check that the parameter values you specify, matches the interpretation used by the chosen function.
