Push_Sign - Texas Instruments TI-89 Developer's Manual

714

push_sign

Declaration: void push_sign (EStackIndex k )
Category(ies): Lists and Matrices
Description: Pushes the sign of the expression indexed by k onto the estack.
sign(positive) -> 1, sign(+0) -> 1, and sign(+0.0) -> 1;
sign(negative) -> L1, sign(L0) -> L1, and sign(L0.0) -> L1;
sign(+Linfinity) -> sign(0) and sign(+LFloatInfinity) -> sign(0.0);
sign(undef) -> sign(0) and sign(NAN) -> sign(0).
For unreal z, sign(z) -> z/abs(z).
If IS_DOMAIN_REAL sign(0) and sign(0.0) represent + L1 and display that
way.
If IS_DOMAIN_COMPLEX, sign(0) displays as sign(0) and sign(0.0)
displays as sign(0.0), both representing the unit circle in the complex plane.
Inputs: k — 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: None
Example:
push_Float (-3.7);
push_sign (top_estack);
TI-89 / TI-92 Plus Developer Guide
Appendix A: System Routines — Lists and Matrices
algebraic comparison, or aggregate thereof.
/* Pushes –1.0 onto the estack. */
Not for Distribution Beta Version January 26, 2001