Texas Instruments TI-89 - Remaining_Factors_Index

296
Appendix A: System Routines — Algebra Utilities
TI
-
89 / TI
-
92 Plus Developer Guide
Not for Distribution
Beta Version January 26, 2001
remaining_factors_index
Declaration:
EStackIndex
remaining_factors_index
(EStackIndex
i
)
Category(ies):
Algebra Utilities
Description:
If
i
indexes a MULTIPLY_TAG, returns the index of the deeper of its two
operands. Otherwise returns Float1Index if IS_ARITH_APPROX is true and
Integer1Index if IS_ARITH_APPROX is false.
For example:
If i indexes the internally-simplified expression
(x^2)
then
remaining_factors_index
(i) returns Float1Index if
IS_ARITH_APPROX is true and Integer1Index if IS_ARITH_APPROX is
false.
Internally-simplified products and ratios have the most main factor
shallowest, with less main factors below that. Also, the lead factor of an
internally-simplified product is never a product.
For example:
If i indexes the internally-simplified expression
(3 * x^2) * y
then
remaining_factors_index
(i) returns index(3
†
y).
For the default mode IS_RECURSIVE, similar powers of the main variable
are collected.
For example:
If i indexes the internally-simplified expression
x^2 * y + x^2
then
remaining_factors_index
(i) returns index(y + 1).
Internally-simplified numeric denominator factors are combined with
numeric numerator factors into a single numeric factor.
For example:
If i indexes the internally-simplified expression
3/2
then
remaining_factors_index
(i) returns Float1Index if
IS_ARITH_APPROX is true and Integer1Index if IS_ARITH_APPROX is
false.
Note that Float1Index and Integer1Index are not normally physically within
the expression indexed by
i
.
(continued)