Procedure

   prsdp_c ( Parse d.p. number with error checking ) 

   void prsdp_c ( ConstSpiceChar     * string,
                  SpiceDouble        * dpval  )

Abstract

   Parse a string as a double precision number, encapsulating error
   handling.

Required_Reading

   None.

Keywords

   NUMBER
   PARSING

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   string     I   String representing a numeric value.
   dpval      O   D.p. value obtained by parsing `string'.

Detailed_Input

   string      is a string representing a numeric value. Commas and
               spaces may be used in this string for ease of reading
               and writing the number. They are treated as
               insignificant but non-error-producing characters.

               For exponential representation any of the characters
               "E","D","e","d" may be used.

               The following are legitimate numeric expressions

                  +12.2 e-1
                  -3. 1415 9276
                  1e12
                  E10

               The program also recognizes the following  mnemonics

                  "PI",  "pi",  "Pi",  "pI"
                  "+PI", "+pi", "+Pi", "+pI"
                  "-PI", "-pi", "-Pi", "-pI"

               and returns the value

                  ( + OR - ) 3.1415 9265 3589 7932 3846 26 ...

               as appropriate.

Detailed_Output

   dpval       is the double precision number obtained by parsing
               `string'.

Parameters

   None.

Exceptions

   1)  If the input string cannot be parsed due to use of an
       unexpected or misplaced character or due to a string
       representing a number too large for double precision, the
       error SPICE(NOTADPNUMBER) is signaled by a routine in the call
       tree of this routine.

   2)  If the `string' input string pointer is null, the error
       SPICE(NULLPOINTER) is signaled.

   3)  If the `string' input string has zero length, the error
       SPICE(EMPTYSTRING) is signaled.

Files

   None.

Particulars

   The purpose of this routine is to enable safe parsing of double
   precision numbers without the necessity of in-line error checking.

Examples

   The numerical results shown for this example may differ across
   platforms. The results depend on the SPICE kernels used as
   input, the compiler and supporting libraries, and the machine
   specific arithmetic implementation.

   1) Parse into a SpiceDouble variable a set of strings
      representing numeric values.


      Example code begins here.


      /.
         Program prsdp_ex1
      ./
      #include <stdio.h>
      #include "SpiceUsr.h"

      int main( )
      {

         /.
         Local parameters.
         ./
         #define SETSIZ       8
         #define STRLEN       12

         /.
         Local variables.
         ./
         SpiceDouble          dpval;

         SpiceInt             i;

         /.
         Initialize the array of strings.
         ./
         SpiceChar            strval [SETSIZ][STRLEN] = {
                                   "100,000,000", " -2 690 192",
                                   "  +12.2 e-1", "-3. 141 592",
                                   "     1.2e12", "        E10",
                                   "         Pi", "        -PI" };

         /.
         Parse each string into a SpiceDouble variable.
         ./
         printf( "   STRVAL               DPVAL\n" );
         printf( "-----------  --------------------------\n" );
         for ( i = 0; i < SETSIZ; i++ )
         {
            prsdp_c ( strval[i], &dpval );

            printf( "%-11s %27.12f\n", strval[i], dpval );
         }

         return ( 0 );
      }


      When this program was executed on a Mac/Intel/cc/64-bit
      platform, the output was:


         STRVAL               DPVAL
      -----------  --------------------------
      100,000,000      100000000.000000000000
       -2 690 192       -2690192.000000000000
        +12.2 e-1              1.220000000000
      -3. 141 592             -3.141592000000
           1.2e12  1200000000000.000000000000
              E10    10000000000.000000000000
               Pi              3.141592653590
              -PI             -3.141592653590

Restrictions

   None.

Literature_References

   None.

Author_and_Institution

   N.J. Bachman        (JPL)
   J. Diaz del Rio     (ODC Space)
   E.D. Wright         (JPL)

Version

   -CSPICE Version 1.1.3, 04-AUG-2021 (JDR)

       Edited the header to comply with NAIF standard. Added complete
       code example.

       Updated the header to properly describe its input, output,
       exceptions and particulars.

   -CSPICE Version 1.1.2, 26-AUG-1999 (NJB)

       Header was updated to list string exceptions.

   -CSPICE Version 1.1.1, 25-MAR-1998 (EDW)

       Minor corrections to header.

   -CSPICE Version 1.1.0, 08-FEB-1998 (NJB)

       References to C2F_CreateStr_Sig were removed; code was
       cleaned up accordingly. String checks are now done using
       the macro CHKFSTR.

   -CSPICE Version 1.0.0, 25-OCT-1997 (NJB)

       Based on SPICELIB Version 1.0.0, 22-JUL-1997 (NJB)

Index_Entries

   parse d.p. number with encapsulated error handling

Link to routine prsdp_c source file prsdp_c.c