| srfc2s_c |
|
Table of contents
Procedure
srfc2s_c ( Surface and body ID codes to surface string )
void srfc2s_c ( SpiceInt code,
SpiceInt bodyid,
SpiceInt srflen,
SpiceChar * srfstr,
SpiceBoolean * isname )
AbstractTranslate a surface ID code, together with a body ID code, to the corresponding surface name. If no such name exists, return a string representation of the surface ID code. Required_ReadingDSK NAIF_IDS KeywordsCONVERSION DSK ID NAME STRING SURFACE Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
code I Integer surface ID code to translate to a string.
bodyid I ID code of body associated with surface.
srflen I Maximum length of output `srfstr'.
srfstr O String corresponding to surface ID code.
isname O Logical flag indicating output is a surface name.
SPICE_SRF_SFNMLN
P Maximum length of surface name.
Detailed_Input
code is an integer code for a surface associated with a
body.
bodyid is an integer code for the body associated with the
surface designated by `code'. The combination of `code'
and `bodyid' is to be mapped to a surface name.
srflen is the maximum number of characters that can be
accommodated in the output string `srfstr'. This count
includes room for the terminating null character.
Normally `srflen' should be set to the value of the
parameter SPICE_SRF_SFNMLN.
Detailed_Output
srfstr the name of the surface identified by `code', for the
body designated by `bodyid', if an association exists
between this pair of ID codes and a surface name.
If `code' has more than one translation, then the most
recently defined surface name corresponding to `code' is
returned. `srfstr' will have the exact format (case and
embedded blanks) used in the definition of the
name/code association.
If the input pair of codes does not map to a surface
name, `srfstr' is set to the string representation of
`code'.
`srfstr' should be declared with length
SPICE_SRF_SFNMLN
(see the -Parameters section below).
isname is a logical flag that is SPICETRUE if a surface name
corresponding to the input ID codes was found and
SPICEFALSE otherwise. When `isname' is SPICEFALSE, the output
string `srfstr' contains a string representing the
integer `code'.
Parameters
SPICE_SRF_SFNMLN
is the maximum length of a surface name. This
parameter is declared in the CSPICE header file
SpiceSrf.h
Exceptions
1) If the input surface ID code cannot be mapped to a name, the
output `srfstr' is set to a string representation of the code.
The input body ID is ignored. The output `isname' is set to
SPICEFALSE.
This case is not treated as an error.
2) If the `srfstr' output string pointer is null, the error
SPICE(NULLPOINTER) is signaled.
3) If the `srfstr' output string has length less than two
characters, the error SPICE(STRINGTOOSHORT) is signaled, since
the output string is too short to contain one character of
output data plus a null terminator.
Files
Surface name-to-ID mappings may be defined at run time by loading
text kernels containing kernel variable assignments of the form
NAIF_SURFACE_NAME += ( <surface name 1>, ... )
NAIF_SURFACE_CODE += ( <surface code 1>, ... )
NAIF_SURFACE_BODY += ( <body code 1>, ... )
Above, the Ith elements of the lists on the assignments' right
hand sides together define the Ith surface name/ID mapping.
The same effect can be achieved using assignments formatted as
follows:
NAIF_SURFACE_NAME += <surface name 1>
NAIF_SURFACE_CODE += <surface code 1>
NAIF_SURFACE_BODY += <body code 1>
NAIF_SURFACE_NAME += <surface name 2>
NAIF_SURFACE_CODE += <surface code 2>
NAIF_SURFACE_BODY += <body code 2>
...
Note the use of the
+=
operator; this operator appends to rather than overwrites the
kernel variable named on the left hand side of the assignment.
Particulars
Surfaces are always associated with bodies (which usually are
ephemeris objects). For any given body, a mapping between surface
names and surface ID codes can be established.
Bodies serve to disambiguate surface names and ID codes: the set
of surface names and surface ID codes for a given body can be
thought of as belonging to a name space. A given surface ID code
or surface name may be used for surfaces of multiple bodies,
without conflict.
Associations between surface names and ID codes are always made
via kernel pool assignments; there are no built-in associations.
srfc2s_c is one of four related functions:
srfs2c_c Surface string and body string to surface ID code
srfscc_c Surface string and body ID code to surface ID code
srfc2s_c Surface ID code and body ID code to surface string
srfcss_c Surface ID code and body string to surface string
srfs2c_c, srfc2s_c, srfscc_c, and srfcss_c perform translations between
surface strings and their corresponding integer ID codes.
Refer to naif_ids.req for details concerning adding new surface
name/code associations at run time by loading text kernels.
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) Supposed a text kernel has been loaded that contains
the following assignments:
NAIF_SURFACE_NAME += ( 'MGS MOLA 64 pixel/deg',
'MGS MOLA 128 pixel/deg',
'PHOBOS GASKELL Q512' )
NAIF_SURFACE_CODE += ( 1, 2, 1 )
NAIF_SURFACE_BODY += ( 499, 499, 401 )
Translate each surface and body ID code pair to the
associated surface name. Also perform a translation
for a surface ID having no matching name.
Use the meta-kernel shown below to define the required SPICE
kernel variables.
KPL/MK
File: srfc2s_ex1.tm
This meta-kernel is intended to support operation of SPICE
example programs. The file contents shown here should not be
assumed to contain adequate or correct versions of data
required by SPICE-based user applications.
\begindata
NAIF_SURFACE_NAME += ( 'MGS MOLA 64 pixel/deg',
'MGS MOLA 128 pixel/deg',
'PHOBOS GASKELL Q512' )
NAIF_SURFACE_CODE += ( 1, 2, 1 )
NAIF_SURFACE_BODY += ( 499, 499, 401 )
\begintext
End of meta-kernel
Example code begins here.
/.
Program srfc2s_ex1
./
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
Local constants
./
#define NCASE 5
/.
Local variables
./
SpiceBoolean isname;
SpiceChar srfnam [ SPICE_SRF_SFNMLN ];
static SpiceChar tf [2][6] =
{ "false", "true" };
SpiceChar * meta;
static SpiceInt bodyid [NCASE] =
{ 499, 401, 499, 499, -1 };
static SpiceInt surfid [NCASE] =
{ 1, 1, 2, 3, 1 };
SpiceInt i;
meta = "srfc2s_ex1.tm";
furnsh_c ( meta );
printf ( "\n" );
for ( i = 0; i < NCASE; i++ )
{
srfc2s_c ( surfid[i], bodyid[i], SPICE_SRF_SFNMLN,
srfnam, &isname );
printf ( "surface ID = %d\n"
"body ID = %d\n"
"name found = %s\n"
"surface string = %s\n\n",
(int) surfid[i],
(int) bodyid[i],
tf[isname],
srfnam );
}
return ( 0 );
}
When this program was executed on a Mac/Intel/cc/64-bit
platform, the output was:
surface ID = 1
body ID = 499
name found = true
surface string = MGS MOLA 64 pixel/deg
surface ID = 1
body ID = 401
name found = true
surface string = PHOBOS GASKELL Q512
surface ID = 2
body ID = 499
name found = true
surface string = MGS MOLA 128 pixel/deg
surface ID = 3
body ID = 499
name found = false
surface string = 3
surface ID = 1
body ID = -1
name found = false
surface string = 1
RestrictionsNone. Literature_ReferencesNone. Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) B.V. Semenov (JPL) E.D. Wright (JPL) Version
-CSPICE Version 1.0.1, 10-AUG-2021 (JDR)
Edited the header to comply with NAIF standard.
-CSPICE Version 1.0.0, 05-APR-2017 (NJB) (BVS) (EDW)
Index_Entriessurface ID code and body ID code to surface string |
Fri Dec 31 18:41:13 2021