Three-dimensional graphics, The variable eq, Examples of interactive plots using the plot menu – HP 48gII User Manual
Page 731

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:
• Dimensions of the view parallelepiped (x
left
, x
right
, y
near
, y
far
,
z
low
, z
high
)
• Range of x and y independent variables (x
min
, x
max
, y
min
, y
max
)
• Location of viewpoint (x
eye
, y
eye
, z
eye
)
• 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
ΣDAT, 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
ΣPAR, 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