Ng_Control - Texas Instruments TI-89 Developer's Manual

Appendix B: Global Variables — Algebra Utilities

NG_control

Declaration: CONTROL_BITS NG_control
Category(ies): Algebra Utilities
Description: The bits in this variable control various computational and formatting
modes. These bits are restored at the beginning of each interaction cycle.
They should be queried only via the various IS_ . . . macros and altered
only via the various SET_ . . . macros described below.
In most cases it is courteous to restore existing modes as soon as you no
longer need to force them. The best way to do this is to capture the entire
previous settings by an assignment such as
Then execute an assignment
no longer need to force any modes. Encapsulate this block of code using
TRY, ONERR and ENDTRY if there is a chance of an exception bypassing
the restoration assignment.
SET_DOMAIN_REAL
SET_DOMAIN_COMPLEX
IS_DOMAIN_REAL
IS_DOMAIN_COMPLEX
SET_COMPLEX_RECTANGULAR_FORM
SET_COMPLEX_EXPONENTIAL_FORM
SET_COMPLEX_FORMAT_AUTO
IS_COMPLEX_RECTANGULAR_FORM
IS_COMPLEX_EXPONENTIAL_FORM
IS_COMPLEX_FORMAT_AUTO
SET_RADIANS
SET_DEGREES
IS_RADIANS
IS_DEGREES
SET_ARITH_EXACT
SET_ARITH_APPROX
SET_ARITH_AUTO
IS_ARITH_EXACT
IS_ARITH_APPROX
IS_ARITH_AUTO
SET_EXPAND_KERNELS
TI-89 / TI-92 Plus Developer Guide
NG_control = old_NG_control
— Use whichever form is most
— Expand ln(),
(continued)
Not for Distribution
old_NG_control = NG_control
as soon as you
compact for each nonreal
subexpression.
^(), abs() etc. in results.
e
Beta Version January 26, 2001
1205
.