drygdryg/calc
1
0
Fork 0
mirror of https://github.com/lcn2/calc.git synced 2025-08-16 01:03:29 +03:00
Code Issues Packages Projects Releases Wiki Activity

Added initial code for d2r() & r2d() builtins

Browse Source 
We still need to add:

    help files for d2r & r2d
    regression tests for d2r & r2d
    notes in related trig help files
    note in unexpected help file
    note in CHANGES
This commit is contained in:
Landon Curt Noll
2021-09-07 04:49:54 -07:00
parent cd736fdbd4
commit 45665f94a7
4 changed files with 170 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

85
qtrans.c
View File

@@ -47,7 +47,26 @@ NUMBER _qlge_ = { { _qlgenum_, 1, 0 }, { _qlgeden_, 1, 0 }, 1, NULL };
STATIC NUMBER *ln_10 = NULL;
STATIC NUMBER *ln_10_epsilon = NULL;
STATIC NUMBER *pivalue[2];
/*
* cache pi
*
* pivalue[LAST_PI_EPSILON] - last epsilon used to calculate pi
* pivalue[LAST_PI_VALUE] - last calculated pi
* given pivalue[LAST_PI_EPSILON] epsilon
* pivalue[LAST_PI_DIV_180_EPSILON] last epsilon used to calculate pi/180
* pivalue[LAST_PI_DIV_180] - last calculated pi/180 given
* pivalue[LAST_PI_DIV_180_EPSILON] epsilon
*/
#define PI_CACHE_LEN (4)
#define LAST_PI_EPSILON (0)
#define LAST_PI_VALUE (1)
#define LAST_PI_DIV_180_EPSILON (2)
#define LAST_PI_DIV_180 (3)
STATIC NUMBER *pivalue[PI_CACHE_LEN];
/*
* other static function decls
*/
STATIC NUMBER *qexprel(NUMBER *q, long bitnum);
/*
@@ -725,16 +744,23 @@ qpi(NUMBER *epsilon)
long bits; /* needed number of bits of precision */
long t;
/* firewall */
if (qiszero(epsilon)) {
math_error("zero epsilon value for pi");
/*NOTREACHED*/
}
if (epsilon == pivalue[0])
return qlink(pivalue[1]);
if (pivalue[0]) {
qfree(pivalue[0]);
qfree(pivalue[1]);
/* use pi cache if epsilon marches, else flush if needed */
if (epsilon == pivalue[LAST_PI_EPSILON]) {
return qlink(pivalue[LAST_PI_VALUE]);
}
if (pivalue[LAST_PI_EPSILON]) {
qfree(pivalue[LAST_PI_EPSILON]);
}
if (pivalue[LAST_PI_VALUE]) {
qfree(pivalue[LAST_PI_VALUE]);
}
bits = -qilog2(epsilon) + 4;
if (bits < 4)
bits = 4;
@@ -768,11 +794,54 @@ qpi(NUMBER *epsilon)
zfree(sum);
r = qmappr(t1, epsilon, 24L);
qfree(t1);
pivalue[0] = qlink(epsilon);
pivalue[1] = qlink(r);
pivalue[LAST_PI_EPSILON] = qlink(epsilon);
pivalue[LAST_PI_VALUE] = qlink(r);
return r;
}
/*
* qpidiv180 - calcucalte pi / 180
*
* This function returns pi/180 as used to covert between degrees and radians.
*/
NUMBER *
qpidiv180(NUMBER *epsilon)
{
NUMBER *pi, *pidiv180;
/* firewall */
if (qiszero(epsilon)) {
math_error("zero epsilon value for qpidiv180");
/*NOTREACHED*/
}
/* use pi/180 cache if epsilon marches, else flush if needed */
if (epsilon == pivalue[LAST_PI_DIV_180_EPSILON]) {
return qlink(pivalue[LAST_PI_DIV_180]);
}
if (pivalue[LAST_PI_DIV_180_EPSILON]) {
qfree(pivalue[LAST_PI_DIV_180_EPSILON]);
}
if (pivalue[LAST_PI_DIV_180]) {
qfree(pivalue[LAST_PI_DIV_180]);
}
/* let qpi() returned cached pi or calculate new as needed */
pi = qpi(epsilon);
/* now calculate pi/180 */
pidiv180 = qdivi(pi, 180);
/* cache epsilon and pi/180 */
pivalue[LAST_PI_DIV_180_EPSILON] = qlink(epsilon);
pivalue[LAST_PI_DIV_180] = qlink(pidiv180);
/* return pi/180 */
return pidiv180;
}
/*
* Calculate the exponential function to the nearest or next to nearest
* multiple of the positive number epsilon.