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Diffstat (limited to 'mpc/src/get_x.c')
| -rw-r--r-- | mpc/src/get_x.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/mpc/src/get_x.c b/mpc/src/get_x.c new file mode 100644 index 0000000000..31610ac61d --- /dev/null +++ b/mpc/src/get_x.c @@ -0,0 +1,236 @@ +/* mpc_get_dc, mpc_get_ldc -- Transform mpc number into C complex number + mpc_get_str -- Convert a complex number into a string. + +Copyright (C) 2009, 2010, 2011 INRIA + +This file is part of GNU MPC. + +GNU MPC is free software; you can redistribute it and/or modify it under +the terms of the GNU Lesser General Public License as published by the +Free Software Foundation; either version 3 of the License, or (at your +option) any later version. + +GNU MPC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS +FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for +more details. + +You should have received a copy of the GNU Lesser General Public License +along with this program. If not, see http://www.gnu.org/licenses/ . +*/ + +#include "config.h" + +#ifdef HAVE_COMPLEX_H +#include <complex.h> +#endif + +#ifdef HAVE_LOCALE_H +#include <locale.h> +#endif + +#include <stdio.h> /* for sprintf, fprintf */ +#include <ctype.h> +#include <string.h> +#include "mpc-impl.h" + +#ifdef HAVE_COMPLEX_H +double _Complex +mpc_get_dc (mpc_srcptr op, mpc_rnd_t rnd) { + return I * mpfr_get_d (mpc_imagref (op), MPC_RND_IM (rnd)) + + mpfr_get_d (mpc_realref (op), MPC_RND_RE (rnd)); +} + +long double _Complex +mpc_get_ldc (mpc_srcptr op, mpc_rnd_t rnd) { + return I * mpfr_get_ld (mpc_imagref (op), MPC_RND_IM (rnd)) + + mpfr_get_ld (mpc_realref (op), MPC_RND_RE (rnd)); +} +#endif + + +/* Code for mpc_get_str. The output format is "(real imag)", the decimal point + of the locale is used. */ + +/* mpfr_prec_t can be either int or long int */ +#if (__GMP_MP_SIZE_T_INT == 1) +#define MPC_EXP_FORMAT_SPEC "i" +#elif (__GMP_MP_SIZE_T_INT == 0) +#define MPC_EXP_FORMAT_SPEC "li" +#else +#error "mpfr_exp_t size not supported" +#endif + +static char * +pretty_zero (mpfr_srcptr zero) +{ + char *pretty; + + pretty = mpc_alloc_str (3); + + pretty[0] = mpfr_signbit (zero) ? '-' : '+'; + pretty[1] = '0'; + pretty[2] = '\0'; + + return pretty; +} + +static char * +prettify (const char *str, const mp_exp_t expo, int base, int special) +{ + size_t sz; + char *pretty; + char *p; + const char *s; + mp_exp_t x; + int sign; + + sz = strlen (str) + 1; /* + terminal '\0' */ + + if (special) + { + /* special number: nan or inf */ + pretty = mpc_alloc_str (sz); + strcpy (pretty, str); + + return pretty; + } + + /* regular number */ + + sign = (str[0] == '-' || str[0] == '+'); + + x = expo - 1; /* expo is the exponent value with decimal point BEFORE + the first digit, we wants decimal point AFTER the first + digit */ + if (base == 16) + x <<= 2; /* the output exponent is a binary exponent */ + + ++sz; /* + decimal point */ + + if (x != 0) + { + /* augment sz with the size needed for an exponent written in base + ten */ + mp_exp_t xx; + + sz += 3; /* + exponent char + sign + 1 digit */ + + if (x < 0) + { + /* avoid overflow when changing sign (assuming that, for the + mp_exp_t type, (max value) is greater than (- min value / 10)) */ + if (x < -10) + { + xx = - (x / 10); + sz++; + } + else + xx = -x; + } + else + xx = x; + + /* compute sz += floor(log(expo)/log(10)) without using libm + functions */ + while (xx > 9) + { + sz++; + xx /= 10; + } + } + + pretty = mpc_alloc_str (sz); + p = pretty; + + /* 1. optional sign plus first digit */ + s = str; + *p++ = *s++; + if (sign) + *p++ = *s++; + + /* 2. decimal point */ +#ifdef HAVE_LOCALECONV + *p++ = *localeconv ()->decimal_point; +#else + *p++ = '.'; +#endif + *p = '\0'; + + /* 3. other significant digits */ + strcat (pretty, s); + + /* 4. exponent (in base ten) */ + if (x == 0) + return pretty; + + p = pretty + strlen (str) + 1; + + switch (base) + { + case 10: + *p++ = 'e'; + break; + case 2: + case 16: + *p++ = 'p'; + break; + default: + *p++ = '@'; + } + + *p = '\0'; + + sprintf (p, "%+"MPC_EXP_FORMAT_SPEC, x); + + return pretty; +} + +static char * +get_pretty_str (const int base, const size_t n, mpfr_srcptr x, mpfr_rnd_t rnd) +{ + mp_exp_t expo; + char *ugly; + char *pretty; + + if (mpfr_zero_p (x)) + return pretty_zero (x); + + ugly = mpfr_get_str (NULL, &expo, base, n, x, rnd); + MPC_ASSERT (ugly != NULL); + pretty = prettify (ugly, expo, base, !mpfr_number_p (x)); + mpfr_free_str (ugly); + + return pretty; +} + +char * +mpc_get_str (int base, size_t n, mpc_srcptr op, mpc_rnd_t rnd) +{ + size_t needed_size; + char *real_str; + char *imag_str; + char *complex_str = NULL; + + if (base < 2 || base > 36) + return NULL; + + real_str = get_pretty_str (base, n, mpc_realref (op), MPC_RND_RE (rnd)); + imag_str = get_pretty_str (base, n, mpc_imagref (op), MPC_RND_IM (rnd)); + + needed_size = strlen (real_str) + strlen (imag_str) + 4; + + complex_str = mpc_alloc_str (needed_size); +MPC_ASSERT (complex_str != NULL); + + strcpy (complex_str, "("); + strcat (complex_str, real_str); + strcat (complex_str, " "); + strcat (complex_str, imag_str); + strcat (complex_str, ")"); + + mpc_free_str (real_str); + mpc_free_str (imag_str); + + return complex_str; +} |