Texas Instruments TI-89 - Push_Div_Dif_1 F

278
Appendix A: System Routines — Algebra Utilities
TI
-
89 / TI
-
92 Plus Developer Guide
Not for Distribution
Beta Version January 26, 2001
push_div_dif_1f
Declaration:
void
push_div_dif_1f
(EStackIndex
i
, EStackIndex
vi
, EStackIndex
j
)
Category(ies):
Algebra Utilities
Description:
Pushes onto the estack the forward first difference (TI-BASIC function
avgRC) of the expression indexed by
i
, with respect to the variable indexed
by
vi
, using the expression indexed by
j
as the step size.
For example: avgRC (f(x), x, h) -> (f(x + h) - f(x))/h.
If invoked via the
push_internal_simplify
function,
vi
then
i
are simplified
to deepest variable. However, if the deepest variable value of
vi
has a
such-that or
§
value, that value is substituted for the deepest variable
value after computing the first difference.
For example, avgRC (x^3, x, h) | x = 1 -> h^2 + 3h + 3.
Inputs:
i
— Index of the top tag of an internally-simplified algebraic expression,
comparison or aggregate thereof.
vi
— Index of a variable.
j
— Index of the top tag of an internally-simplified algebraic expression
or an aggregate thereof.
Outputs:
None
Assumptions:
None
Side Effects:
None
Availability:
On AMS 2.02 and higher.
TI
-
89 / TI
-
92 Plus
Differences:
None
See Also: push_div_dif_1c
Example:
push_Float (1e-4);
h = top_estack;
push_quantum (8u);
vi = top_estack; /* Push variable x */
push_quantum (EXP_TAG); /* top_estack -> e^x */
push_div_dif_1f (top_estack, vi, h); /* push avgRC(e^x, x, 1e-4) */