HP 50g Graphing Calculator - Manual (Page 724)

Page 22-9
The PTYPE menu within 3D (IV)
The PTYPE menu under 3D contains the following functions:
These functions correspond to the graphics options Slopefield, Wireframe, Y-
Slice, Ps-Contour, Gridmap and Pr-Surface presented earlier in this chapter.
Pressing one of these soft menu keys, while typing a program, will place the
corresponding function call in the program. Press L
@)@3D@@ to get back to the
main 3D menu.
The VPAR menu within 3D (V)
The variable VPAR stands for Volume PARameters, referring to a parallelepiped
in space within which the three-dimensional graph of interest is constructed.
When press [VPAR] in the 3D menu, you will get the following functions. Press
L
to move to the next menu:
Next, we describe the meaning of these functions:
INFO (S) and VPAR (W)
When you press
@INFO (S) you get the information shown in the left-hand side
screen shot above. The ranges in Xvol, Yvol, and Zvol describe the extent of the
parallelepiped in space where the graph will be generated. Xrng and Yrng
describe the range of values of x and y, respectively, as independent variables
in the x-y plane that will be used to generate functions of the form z = f(x,y).
Press L and @INFO (Y) to obtain the information in the right-hand side screen
shot above. These are the value of the location of the viewpoint for the three-
dimensional graph (Xeye, Yeye, Zeye), and of the number of steps in x and y to
generate a grid for surface plots.