On Sat, 3 Feb 2007 01:46:08 +0100David Nečas (Yeti) <yeti@xxxxxxxxxxxxxxx> wrote: >On Fri, Feb 02, 2007 at 04:14:09PM -0800, Sergei Steshenko wrote:>> >> You can still use explicit cast, i.e.>> >> ((long double)G_PI)>> >> , can't you?>>If you can demonstrate a program that gets the value of G_PI>to a long double with the full precision, please enlighten>me.>Yeti I'll post this in case anyone in the future searches the archivesfor an answer. This works, but it needs the mpfr library and gmp fromhttp://www.mpfr.org/mpfr-current/ /* gcc -o mfpr-test mfpr-test.c `pkg-config --cflags --libs gtk+-2.0` -lgmp -lmpfr */ #include <stdio.h>#include <gmp.h>#include <mpfr.h>#include <gtk/gtk.h> int main (void){ mpfr_t pi,g_pi; mpfr_init2 (pi, 200); mpfr_init2 (g_pi, 200); mpfr_set_ld(pi, 3.1415926535897932384626433832795028841971693993751, GMP_RNDN); mpfr_set_ld(g_pi, G_PI, GMP_RNDN); g_print("PI is "); mpfr_out_str (stdout, 10, 0, pi, GMP_RNDN); g_print("\n"); mpfr_clear (pi); g_print("G_PI is "); mpfr_out_str (stdout, 10, 0, g_pi , GMP_RNDN); g_print("\n"); mpfr_clear (g_pi); return 0;} __END__ Output:PI is 3.1415926535897931159979634685441851615905761718750000000000000G_PI is 3.1415926535897931159979634685441851615905761718750000000000000 However, to be fair to Tor's comments, I did a rudimentary calculation using the15 decimal point version of G_PI ( which is available to the standard libraries).and found the resolutions on the surface of the earth and the moon, to bepretty good ( from the center of the earth asssuming 0.0000000000000001 rad angular resolution )earth res: 0.00000000035 metersmoon res: 0.00000003835 meters So unless I need to find a quarter on Jupiter, I should be OK. :-) One other point though, g_print won't accept the mpfr_t as a long double,so the "%Lf" format won't work. zentara -- I'm not really a human, but I play one on earth.http://zentara.net/japh.html_______________________________________________gtk-list mailing listgtk-list@xxxxxxxxxxxxx://mail.gnome.org/mailman/listinfo/gtk-list
