diff options
Diffstat (limited to 'libX11/src/xcms/cmsMath.c')
-rw-r--r-- | libX11/src/xcms/cmsMath.c | 272 |
1 files changed, 136 insertions, 136 deletions
diff --git a/libX11/src/xcms/cmsMath.c b/libX11/src/xcms/cmsMath.c index 009a623b4..70b067587 100644 --- a/libX11/src/xcms/cmsMath.c +++ b/libX11/src/xcms/cmsMath.c @@ -1,136 +1,136 @@ -
-/*
-
-Copyright 1990, 1998 The Open Group
-
-Permission to use, copy, modify, distribute, and sell this software and its
-documentation for any purpose is hereby granted without fee, provided that
-the above copyright notice appear in all copies and that both that
-copyright notice and this permission notice appear in supporting
-documentation.
-
-The above copyright notice and this permission notice shall be included in
-all copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
-AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-
-Except as contained in this notice, the name of The Open Group shall not be
-used in advertising or otherwise to promote the sale, use or other dealings
-in this Software without prior written authorization from The Open Group.
-
-*/
-
-/*
- * Stephen Gildea, MIT X Consortium, January 1991
- */
-
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
-#include "Xlibint.h"
-#include "Xcmsint.h"
-
-#include <float.h>
-#ifndef DBL_EPSILON
-#define DBL_EPSILON 1e-6
-#endif
-
-#ifdef _X_ROOT_STATS
-int cbrt_loopcount;
-int sqrt_loopcount;
-#endif
-
-/* Newton's Method: x_n+1 = x_n - ( f(x_n) / f'(x_n) ) */
-
-
-/* for cube roots, x^3 - a = 0, x_new = x - 1/3 (x - a/x^2) */
-
-double
-_XcmsCubeRoot(double a)
-{
- register double abs_a, cur_guess, delta;
-
-#ifdef DEBUG
- printf("_XcmsCubeRoot passed in %g\n", a);
-#endif
-#ifdef _X_ROOT_STATS
- cbrt_loopcount = 0;
-#endif
- if (a == 0.)
- return 0.;
-
- abs_a = a<0. ? -a : a; /* convert to positive to speed loop tests */
-
- /* arbitrary first guess */
- if (abs_a > 1.)
- cur_guess = abs_a/8.;
- else
- cur_guess = abs_a*8.;
-
- do {
-#ifdef _X_ROOT_STATS
- cbrt_loopcount++;
-#endif
- delta = (cur_guess - abs_a/(cur_guess*cur_guess))/3.;
- cur_guess -= delta;
- if (delta < 0.) delta = -delta;
- } while (delta >= cur_guess*DBL_EPSILON);
-
- if (a < 0.)
- cur_guess = -cur_guess;
-
-#ifdef DEBUG
- printf("_XcmsCubeRoot returning %g\n", cur_guess);
-#endif
- return cur_guess;
-}
-
-
-
-/* for square roots, x^2 - a = 0, x_new = x - 1/2 (x - a/x) */
-
-double
-_XcmsSquareRoot(double a)
-{
- register double cur_guess, delta;
-
-#ifdef DEBUG
- printf("_XcmsSquareRoot passed in %g\n", a);
-#endif
-#ifdef _X_ROOT_STATS
- sqrt_loopcount = 0;
-#endif
- if (a == 0.)
- return 0.;
-
- if (a < 0.) {
- /* errno = EDOM; */
- return 0.;
- }
-
- /* arbitrary first guess */
- if (a > 1.)
- cur_guess = a/4.;
- else
- cur_guess = a*4.;
-
- do {
-#ifdef _X_ROOT_STATS
- sqrt_loopcount++;
-#endif
- delta = (cur_guess - a/cur_guess)/2.;
- cur_guess -= delta;
- if (delta < 0.) delta = -delta;
- } while (delta >= cur_guess*DBL_EPSILON);
-
-#ifdef DEBUG
- printf("_XcmsSquareRoot returning %g\n", cur_guess);
-#endif
- return cur_guess;
-}
-
+ +/* + +Copyright 1990, 1998 The Open Group + +Permission to use, copy, modify, distribute, and sell this software and its +documentation for any purpose is hereby granted without fee, provided that +the above copyright notice appear in all copies and that both that +copyright notice and this permission notice appear in supporting +documentation. + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN +AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + +Except as contained in this notice, the name of The Open Group shall not be +used in advertising or otherwise to promote the sale, use or other dealings +in this Software without prior written authorization from The Open Group. + +*/ + +/* + * Stephen Gildea, MIT X Consortium, January 1991 + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif +#include "Xlibint.h" +#include "Xcmsint.h" + +#include <float.h> +#ifndef DBL_EPSILON +#define DBL_EPSILON 1e-6 +#endif + +#ifdef _X_ROOT_STATS +int cbrt_loopcount; +int sqrt_loopcount; +#endif + +/* Newton's Method: x_n+1 = x_n - ( f(x_n) / f'(x_n) ) */ + + +/* for cube roots, x^3 - a = 0, x_new = x - 1/3 (x - a/x^2) */ + +double +_XcmsCubeRoot(double a) +{ + register double abs_a, cur_guess, delta; + +#ifdef DEBUG + printf("_XcmsCubeRoot passed in %g\n", a); +#endif +#ifdef _X_ROOT_STATS + cbrt_loopcount = 0; +#endif + if (a == 0.) + return 0.; + + abs_a = a<0. ? -a : a; /* convert to positive to speed loop tests */ + + /* arbitrary first guess */ + if (abs_a > 1.) + cur_guess = abs_a/8.; + else + cur_guess = abs_a*8.; + + do { +#ifdef _X_ROOT_STATS + cbrt_loopcount++; +#endif + delta = (cur_guess - abs_a/(cur_guess*cur_guess))/3.; + cur_guess -= delta; + if (delta < 0.) delta = -delta; + } while (delta >= cur_guess*DBL_EPSILON); + + if (a < 0.) + cur_guess = -cur_guess; + +#ifdef DEBUG + printf("_XcmsCubeRoot returning %g\n", cur_guess); +#endif + return cur_guess; +} + + + +/* for square roots, x^2 - a = 0, x_new = x - 1/2 (x - a/x) */ + +double +_XcmsSquareRoot(double a) +{ + register double cur_guess, delta; + +#ifdef DEBUG + printf("_XcmsSquareRoot passed in %g\n", a); +#endif +#ifdef _X_ROOT_STATS + sqrt_loopcount = 0; +#endif + if (a == 0.) + return 0.; + + if (a < 0.) { + /* errno = EDOM; */ + return 0.; + } + + /* arbitrary first guess */ + if (a > 1.) + cur_guess = a/4.; + else + cur_guess = a*4.; + + do { +#ifdef _X_ROOT_STATS + sqrt_loopcount++; +#endif + delta = (cur_guess - a/cur_guess)/2.; + cur_guess -= delta; + if (delta < 0.) delta = -delta; + } while (delta >= cur_guess*DBL_EPSILON); + +#ifdef DEBUG + printf("_XcmsSquareRoot returning %g\n", cur_guess); +#endif + return cur_guess; +} + |