Merge commit '7fde2daeed593684120d75de07598154f3ddaf2c' as 'ast'

1 files changed, 181 insertions, 0 deletions

diff --git a/ast/astbad.c b/ast/astbad.c
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+++ b/ast/astbad.c
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+/* Header files. */
+/* ============= */
+/* Interface definitions. */
+/* ---------------------- */
+#include "pointset.h"           /* declaration of AST__BAD etc */
+
+/* C header files. */
+/* --------------- */
+#include <float.h>
+#include <stdio.h>
+#include <string.h>
+
+/* Local Constants: */
+#define BUFF_LEN ( 2 * DBL_DIG + 20 ) /* Buffer length */
+#define IEEE_DIG 17                   /* Minimum number of digits required by
+                                         IEEE for conversion from binary to
+                                         string and back again to be an
+                                         identity. */
+
+/* Prototypes for local functions */
+static void printdval( double );
+static void printfval( float );
+
+/* Main function. */
+/* ============== */
+int main( int argc, char *argv[] ) {
+/*
+*+
+*  Name:
+*     astbad
+
+*  Purpose:
+*     Generate a string representing an AST floating point constant.
+
+*  Invocation:
+*     astbad <value>
+
+*  Type:
+*     C program.
+
+*  Description:
+*     This program writes a string to standard output containing
+*     a formatted decimal representation of a specified C floating point
+*     constant defined by AST. This is intended for use in defining these
+*     constants for use from languages other than C.
+*
+*     The value written should contain sufficient decimal digits so
+*     that a routine that uses it to generate a value in another
+*     language will produce exactly the same value as a C program
+*     using the same macro.
+
+*  Arguments:
+*     value = LITERAL
+*        The name of the constant to be printed: AST__BAD, AST__NAN or
+*        AST__NANF. If not supplied, AST__BAD is printed.
+
+*  Copyright:
+*     Copyright (C) 2009-2011 Science & Technology Facilities Council.
+*     Copyright (C) 1997-2006 Council for the Central Laboratory of the
+*     Research Councils
+
+*  Licence:
+*     This program 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.
+*     
+*     This program 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
+*     License along with this program.  If not, see
+*     <http://www.gnu.org/licenses/>.
+
+*  Authors:
+*     RFWS: R.F. Warren-Smith (Starlink)
+*     DSB: David S. Berry (Starlink)
+*     TIMJ: Tim Jenness (JAC, Hawaii)
+
+*  History:
+*     18-NOV-1997 (RFWS);
+*        Original version.
+*     24-OCT-2000 (DSB):
+*        Ensure that the number of digits used is at least the minimum
+*        required by IEEE for a conversion from binary to string and back
+*        to binary to be an identity.
+*     31-MAR-2009 (TIMJ):
+*        Does not take any arguments so don't try to read arguments.
+*     18-JAN-2011 (DSB):
+*        Extend to print other floating point constants as well as
+*        AST__BAD.
+*-
+*/
+
+/* Local Variables; */
+   const char *name;        /* Pointer to name of constant to be printed */
+
+/* Get the name of the constant to be printed. */
+   if( argc > 1 ) {
+      name = argv[1];
+   } else {
+      name = "AST__BAD";
+   }
+
+/* Print it. */
+   if( !strcmp( name, "AST__BAD" ) ) {
+      printdval( AST__BAD );
+
+   } else if( !strcmp( name, "AST__NAN" ) ) {
+      printdval( AST__NAN );
+
+   } else if( !strcmp( name, "AST__NANF" ) ) {
+      printfval( AST__NANF );
+
+/* Issue an error message if the argument is unknown. */
+   } else {
+      (void) fprintf( stderr, "astbad: Unknown constant requested: %s\n",
+                      name );
+   }
+
+/* Exit. */
+   return 0;
+}
+
+
+/* Print a double precision value to standard output */
+static void printdval( double val ){
+
+/* Local Variables: */
+   char buff[ BUFF_LEN + 1 ];    /* Buffer for formatted string */
+   double newval;                /* Value read back from string */
+   int digits;                   /* Number of digits of precision */
+
+/* Vary the precision over a reasonable range to see how many decimal
+   digits are required. The initial number of digits is the larger of
+   DBL_DIG and IEEE_DIG. */
+   for ( digits = ( DBL_DIG > IEEE_DIG )?DBL_DIG:IEEE_DIG;
+         digits <= ( 2 * DBL_DIG ); digits++ ) {
+
+/* Format the value using this precision and then read it back. */
+      (void) sprintf( buff, "%.*G", digits, val );
+      (void) sscanf( buff, "%lg", &newval );
+
+/* Quit looping when the original value is read back. */
+      if ( newval == val ) break;
+   }
+
+/* Write the value to standard output, with one extra digit for good
+   measure. */
+   (void) printf( "%.*G\n", digits + 1, val );
+}
+
+/* Print a single precision value to standard output */
+static void printfval( float val ){
+
+/* Local Variables: */
+   char buff[ BUFF_LEN + 1 ];    /* Buffer for formatted string */
+   float newval;                 /* Value read back from string */
+   int digits;                   /* Number of digits of precision */
+
+/* Vary the precision over a reasonable range to see how many decimal
+   digits are required. The initial number of digits is FLT_DIG. */
+   for ( digits = FLT_DIG; digits <= ( 2 * FLT_DIG ); digits++ ) {
+
+/* Format the value using this precision and then read it back. */
+      (void) sprintf( buff, "%.*G", digits, val );
+      (void) sscanf( buff, "%g", &newval );
+
+/* Quit looping when the original value is read back. */
+      if ( newval == val ) break;
+   }
+
+/* Write the value to standard output, with one extra digit for good
+   measure. */
+   (void) printf( "%.*G\n", digits + 1, val );
+
+}
+