The Built-In Variable Fldpic; Displaying The Graph - Texas Instruments TI-86 Manual Book

138
Chapter 10: Differential Equation Graphing
Stat plot and screen drawings
are not stored to .
fldPic

The Built-In Variable fldPic

As the TI-86 plots a field, it stores the field and any displayed label, axes, or cursor
coordinate information to the built-in variable
These actions do not update
Switching the solving method format from
Entering or editing any initial condition variable value (
Editing a value for
difTol
Changing a graph style
These actions update
fldPic
Editing an equation in the equation editor
Re-assigning an axis, editing a
Using a
GRAPH ZOOM
Changing a format setting other than solving method format
Editing a value for
xMin

Displaying the Graph

To plot the differential equations, you can select
, , or operation, from the
DRAW ZOOM STPIC
from to . If is not an axis, it plots each point beginning at
tMin tMax t
begins at . As a graph is plotted, the variables
tMin
affects trace resolution and graph appearance, but not the accuracy of the trace
tStep
values. does not determine the step size for solving; using the
tStep
Kutta 2-3) determines the step size. If the x-axis is
increases plotting time without increasing accuracy.
fldPic
.
fldPic
RK
, , , ,
EStep tMin tMax tStep
.
value, or editing a
dTime
menu item
, , , ,
xMax xScl yMin yMax
GRAPH
GRAPH
.
to or from to
Euler Euler
through
Q[1 Q[9
, or
tPlot
value
fldRes
, or
yScl
, , , or
TRACE EVAL
menu. The TI-86 solves each equation
; otherwise, it
tPlot
, , , and n are updated.
x y t Q
algorithm (Runge-
RK
, setting <( tMax N tMin
t tStep
RK
)
, or a
STGDB
)à126