Texas Instruments TI-89 Manual Book page 175

Window Variables
Note: If you enter a
fractional number for xgrid
or ygrid , it is rounded to the
nearest whole number ‚ 1.
Note: The 3D mode does
not have scl Window
variables, so you cannot set
tick marks on the axes.
Note: Increasing the grid
variables decreases the
graphing speed.
158 Chapter 10: 3D Graphing
The Window Editor maintains an independent set of Window
variables for each
Graph
maintains independent function lists). 3D graphs use the following
Window variables.
Variable Description
Angles (always in degrees) used to view the graph.
eyeq, eyef,
Refer to "Rotating and/or Elevating the Viewing Angle"
eye
on page 162.
, , Boundaries of the viewing cube.
xmin xmax
,
ymin ymax,
zmin, zmax
The distance between
xgrid, ygrid
and
ymax
The
z(x,y)
where the grid lines (or grid wires) intersect.
The incremental value along
x increment =
The number of grid wires is
example, when
consists of 225 (15
z(xmin,ymin)
z(xmax,ymin)
The number of contours evenly distributed along the
ncontour
displayed range of z values. Refer to page 168.
Standard values (set when you select
toolbar menu) are:
xmin = ë 10.
eyeq = 20.
eyef = 70. xmax = 10.
eye = 0. xgrid = 14.
You may need to increase the standard values for the
( , ) to ensure that enough points are plotted.
xgrid ygrid
mode setting (just as the Y= Editor
and
xmin xmax
is divided into the specified number of grids.
equation is evaluated at each grid point
and
x
xmax ì xmin
y increment =
xgrid
xgrid + 1
and
xgrid = 14 ygrid = 14
15) grid points.
6:ZoomStd
ymin = ë 10.
ymax = 10.
ygrid = 14.
and between
ymin
is calculated as:
y
ymax ì ymin
ygrid
and . For
ygrid + 1
, the xy grid
z(xmin,ymax)
z(xmax,ymax)
from the „
Zoom
zmin = ë 10.
zmax = 10.
ncontour = 5.
variables
grid