HP 50G, Руководство пользователя

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Page 12-42
For example, to produce a Pr-Surface plot for the surface x = x(X,Y) = X sin Y, y
= y(X,Y) = x cos Y, z=z(X,Y)=X, use the following:
Θ
Press
„ô
, simultaneously if in RPN mode, to access to the PLOT
SETUP window.
Θ
Change
TYPE
to
Pr-Surface.
Θ
Press
˜
and type ‘{X*SIN(Y), X*COS(Y), X}’
@@@OK@@@
.
Θ
Make sure that ‘X’ is selected as the
Indep:
and ‘Y’ as the
Depnd
:
variables.
Θ
Press
L @@@OK@@@
to return to normal calculator display.
Θ
Press
„ò
, simultaneously if in RPN mode, to access the PLOT
WINDOW screen.
Θ
Keep the default plot window ranges to read:
X-Left:-1, X-Right:1, Y-Near:-1, Y-
Far: 1, Z-Low: -1, Z-High:1, XE: 0, YE:-3, zE:0,
Step Indep: 10, Depnd: 8
Θ
Press
@ERASE @DRAW
to draw the three-dimensional surface.
Θ
Press
@EDIT ! L @LABEL @MENU
to see the graph with labels and ranges.
Θ
Press
LL @)PICT @CANCL
to return to the PLOT WINDOW environment.
Θ
Press
$
, or
L @@@OK@@@
, to return to normal calculator display.
The VPAR variable
The VPAR (Volume Parameter) variable contains information regarding the
“volume” used to produce a three dimensional graph. Therefore, you will see it
produced whenever you create a three dimensional plot such as Fast3D,
Wireframe, or Pr-Surface.
Note : The equations x = x(X,Y), y = y(X,Y), z=z(X,Y) represent a parametric
description of a surface. X and Y are the independent parameters. Most
textbooks will use (u,v) as the parameters, rather than (X,Y). Thus, the
parametric description of a surface is given as x = x(u,v), y = y(u,v), z=z(u,v).