* functions. */
/*
- * GiNaC Copyright (C) 1999-2005 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2010 Johannes Gutenberg University Mainz, Germany
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#include <vector>
-#include <stdexcept>
-
#include "inifcns.h"
#include "ex.h"
#include "constant.h"
#include "pseries.h"
#include "utils.h"
+#include <stdexcept>
+#include <vector>
+
namespace GiNaC {
//////////
static ex log_real_part(const ex & x)
{
+ if (x.info(info_flags::nonnegative))
+ return log(x).hold();
return log(abs(x));
}
static ex log_imag_part(const ex & x)
{
+ if (x.info(info_flags::nonnegative))
+ return 0;
return atan2(GiNaC::imag_part(x), GiNaC::real_part(x));
}
static ex atan2_eval(const ex & y, const ex & x)
{
- if (y.info(info_flags::numeric) && x.info(info_flags::numeric)) {
+ if (y.is_zero()) {
- if (y.is_zero()) {
+ // atan(0, 0) -> 0
+ if (x.is_zero())
+ return _ex0;
- // atan(0, 0) -> 0
- if (x.is_zero())
- return _ex0;
+ // atan(0, x), x real and positive -> 0
+ if (x.info(info_flags::positive))
+ return _ex0;
- // atan(0, x), x real and positive -> 0
- if (x.info(info_flags::positive))
- return _ex0;
+ // atan(0, x), x real and negative -> Pi
+ if (x.info(info_flags::negative))
+ return Pi;
+ }
- // atan(0, x), x real and negative -> -Pi
- if (x.info(info_flags::negative))
- return _ex_1*Pi;
- }
+ if (x.is_zero()) {
- if (x.is_zero()) {
+ // atan(y, 0), y real and positive -> Pi/2
+ if (y.info(info_flags::positive))
+ return _ex1_2*Pi;
- // atan(y, 0), y real and positive -> Pi/2
- if (y.info(info_flags::positive))
- return _ex1_2*Pi;
+ // atan(y, 0), y real and negative -> -Pi/2
+ if (y.info(info_flags::real) && !y.is_zero())
+ return _ex_1_2*Pi;
+ }
- // atan(y, 0), y real and negative -> -Pi/2
- if (y.info(info_flags::negative))
- return _ex_1_2*Pi;
- }
+ if (y.is_equal(x)) {
- if (y.is_equal(x)) {
+ // atan(y, y), y real and positive -> Pi/4
+ if (y.info(info_flags::positive))
+ return _ex1_4*Pi;
- // atan(y, y), y real and positive -> Pi/4
- if (y.info(info_flags::positive))
- return _ex1_4*Pi;
+ // atan(y, y), y real and negative -> -3/4*Pi
+ if (y.info(info_flags::negative))
+ return numeric(-3, 4)*Pi;
+ }
- // atan(y, y), y real and negative -> -3/4*Pi
- if (y.info(info_flags::negative))
- return numeric(-3, 4)*Pi;
- }
+ if (y.is_equal(-x)) {
- if (y.is_equal(-x)) {
+ // atan(y, -y), y real and positive -> 3*Pi/4
+ if (y.info(info_flags::positive))
+ return numeric(3, 4)*Pi;
- // atan(y, -y), y real and positive -> 3*Pi/4
- if (y.info(info_flags::positive))
- return numeric(3, 4)*Pi;
+ // atan(y, -y), y real and negative -> -Pi/4
+ if (y.info(info_flags::negative))
+ return _ex_1_4*Pi;
+ }
- // atan(y, -y), y real and negative -> -Pi/4
- if (y.info(info_flags::negative))
- return _ex_1_4*Pi;
- }
+ // atan(float, float) -> float
+ if (is_a<numeric>(y) && !y.info(info_flags::crational) &&
+ is_a<numeric>(x) && !x.info(info_flags::crational))
+ return atan(ex_to<numeric>(y), ex_to<numeric>(x));
- // atan(float, float) -> float
- if (!y.info(info_flags::crational) && !x.info(info_flags::crational))
- return atan(ex_to<numeric>(y), ex_to<numeric>(x));
-
- // atan(real, real) -> atan(y/x) +/- Pi
- if (y.info(info_flags::real) && x.info(info_flags::real)) {
- if (x.info(info_flags::positive))
- return atan(y/x);
- else if(y.info(info_flags::positive))
- return atan(y/x)+Pi;
- else
- return atan(y/x)-Pi;
- }
+ // atan(real, real) -> atan(y/x) +/- Pi
+ if (y.info(info_flags::real) && x.info(info_flags::real)) {
+ if (x.info(info_flags::positive))
+ return atan(y/x);
+ else if (y.info(info_flags::positive))
+ return atan(y/x)+Pi;
+ else
+ return atan(y/x)-Pi;
}
return atan2(y, x).hold();