HP 50G, User Manual

Page: 730 / 887

Page 22-15
Three-dimensional graphics
The three-dimensional graphics available, namely, options Slopefield,
Wireframe, Y-Slice, Ps-Contour, Gridmap and Pr-Surface , use the VPAR variable
with the following format:
{
x
left
, x
right
, y
near
, y
far
, z
low
, z
high
, x
min
, x
max
, y
min
, y
max
,
x
eye
, y
eye
, z
eye
, x
step
, y
step
}
These pairs of values of x, y, and z, represent the following:
Θ
Dimensions of the view parallelepiped (
x
left
, x
right
, y
near
, y
far
,
z
low
, z
high
)
Θ
Range of x and y independent variables (
x
min
, x
max
, y
min
, y
max
)
Θ
Location of viewpoint (
x
eye
, y
eye
, z
eye
)
Θ
Number of steps in the x- and y-directions (
x
step
, y
step
)
Three-dimensional graphics also require the PPAR variable with the parameters
shown above.
The variable EQ
All plots, except those based on
Σ
DAT, also require that you define the function
or functions to be plotted by storing the expressions or references to those
functions in the variable EQ.
In summary, to produce a plot in a program you need to load EQ, if required.
Then load PPAR, PPAR and
Σ
PAR, or PPAR and VPAR. Finally, use the name of
the proper plot type: FUNCTION, CONIC, POLAR, PARAMETRIC, TRUTH,
DIFFEQ, BAR, HISTOGRAM, SCATTER, SLOPE, WIREFRAME, YSLICE,
PCONTOUR, GRIDMAP, or PARSURFACE, to produce your plot.
Examples of interactive plots using the PLOT menu
To better understand the way a program works with the PLOT commands and
variables, try the following examples of interactive plots using the PLOT menu.
Example 1 – A function plot:
„ÌC
Get PLOT menu (*)
@)PTYPE @FUNCT
Select FUNCTION as the plot type
‘
√
r’
`„
@@EQ@@
Store function ‘
√
r’ into EQ