Texas Instruments TI-89 - Push_Numerator

286
Appendix A: System Routines — Algebra Utilities
TI
-
89 / TI
-
92 Plus Developer Guide
Not for Distribution
Beta Version January 26, 2001
push_numerator
Declaration:
void
push_numerator
(EStackIndex
i
)
Category(ies):
Algebra Utilities
Description:
Pushes onto the estack the syntactic numerator of expression
i
.
The numerator of a float or integer is the float or integer.
DIVIDE_TAG does not occur in internally-simplified expressions, so:
•
The numerator of a power is the power if the degree is positive;
otherwise the numerator is 1.0 or 1 depending on IS_ARITH_APPROX.
•
The numerator of a product is the product of the factors that do not
have negative degrees.
•
Otherwise the numerator is the entire expression.
Note that:
The numerator of 1.5 is 1.5.
The numerator of x^-2 is 1.0 or 1 depending on IS_ARITH_APPROX.
The numerator of x
†
(y + 1)^-1
†
y^-1
†
3 is x
†
3.
The numerator of x^-1 + 3 is the entire expression.
Inputs:
i
— Indexes the top tag of an internally-simplified algebraic expression.
Outputs:
None
Assumptions:
None
Side Effects:
None
Availability:
On AMS 2.02 and higher.
TI
-
89 / TI
-
92 Plus
Differences:
None
See Also: push_denominator
Example:
void push_numerator_of_com_denom (EStackIndex i)
/* Pushes the numerator of the expression that would be obtained by
putting the expression indexed by i over a common denominator.
*/
{ Access_AMS_Global_Variables;
EStackIndex old_top = top_estack;
push_standardize (i);
i = top_estack;
push_numerator (i);
delete_between (old_top, i);
}