Exemplo n.º 1
0
int main( int argc, char **argv ){

/* Local variables: */
   AstBox *pixbox;
   AstFitsChan *fchan;
   AstFrame *pixfrm;
   AstFrame *wcsfrm;
   AstFrameSet *frameset;
   AstKeyMap *warnings;
   AstMapping *pix2wcs;
   AstObject *object;
   AstRegion *wcsbox;
   AstStcsChan *schan;
   FILE *fd;
   char key[ 15 ];
   char keyword[ 9 ];
   const char *message;
   double p1[ MAX_AXES ];
   double p2[ MAX_AXES ];
   int axis;
   int iwarn;
   int naxis;
   int status;

/* Initialised the returned system status to indicate success. */
   status = 0;

/* Check a file was specified on the command line, and attempt to open it
   for read access. */
   if( argc < 2 ) {
      printf( "Usage: stcschan-demo2 <header-file>\n" );
      status = 1;
   } else {
      fd = fopen( argv[ 1 ], "r" );
      if( !fd ) {
         printf("Failed to open input file '%s'.\n", argv[ 1 ] );
         status = 1;
      }
   }

/* If a disk file was opened successfully... */
   if( !status ) {

/* Start an AST object context. This means we do not need to annull
   each AST Object individually. Instead, all Objects created within
   this context will be annulled automatically by the corresponding
   invocation of astEnd. */
      astBegin;

/* Create a FitsChan. This is the object that converts external FITS
   headers into corresponding AST Objects. Tell it to use the "source"
   function for obtaining lines of text from the disk file. */
      fchan = astFitsChan( source, NULL, " " );

/* Associate the descriptor for the input disk file with the StcsChan.
   This makes it available to the "source" function. Since this
   application is single threaded, we could instead have made "fd" a
   global variable, but the ChannelData facility is used here to illustrate
   how to pass data to a source or sink function safely in a multi-threaded
   application. */
      astPutChannelData( fchan, fd );

/* Attempt to read the FITS heades and convert them into an AST FrameSet. */
      object = astRead( fchan );

/* The astRead function is a generic function and so returns a generic
   AstObject pointer. Check an Object was created successfully. */
      if( !object ) {
         printf( "Failed to read an AST Object from file '%s'.\n",
                 argv[ 1 ] );
         status = 1;

/* Now check that the object read is actually an AST FrameSet, rather than
   some other class of AST Object. */
      } else if( !astIsAFrameSet( object ) ) {
         printf( "Expected a FrameSet but read a %s from file '%s'.\n",
                 astGetC( object, "Class" ), argv[ 1 ] );
         status = 1;

/* We now know we have a FrameSet so it is safe to use the pointer
   returned by astRead as a FrameSet pointer. Do the cast now to avoid
   repeated casting in future. */
      } else {
         frameset = (AstFrameSet *) object;

/* Get a pointer to the Frame that describes the attributes of the FITS
   world coordinate system. This is the current Frame in the FrameSet
   read from the FITS headers. */
         wcsfrm = astGetFrame( frameset, AST__CURRENT );

/* Get a pointer to the Frame that describes the attributes of the FITS
   pixel coordinate system. This is the base Frame in the FrameSet
   read from the FITS headers. */
         pixfrm = astGetFrame( frameset, AST__BASE );

/* Get the Mapping that transforms pixel positions into WCS positions.
   The is the Mapping from base to current Frame in the  FrameSet read
   from the FITS headers. */
         pix2wcs = astGetMapping( frameset, AST__BASE, AST__CURRENT );

/* Get the number of axes in ther pixel Frame. */
         naxis = astGetI( pixfrm, "Naxes" );

/* For each pixel axis, form the name of the corresponding NAXISi
   keyword. */
         for( axis = 0; axis < naxis; axis++ ) {
            sprintf( keyword, "NAXIS%d", axis + 1 );

/* Store the pixel coordinate on the current axis at the lower left corner
   of the first pixel. */
            p1[ axis ] = 0.5;

/* Get the NAXISi value for the current axis from the FITS header, and
   store it in array "p2". Report an error if NAXISi is not found. */
            if( !astGetFitsF( fchan, keyword, p2 + axis ) ){
               printf("Keyword '%s' not found in header\n", keyword );
               status = 1;
               break;

/* If it is found, modify "p2" so that it holds the pixel coordinate on
   the current axis at the upper right corner of the last pixel. */
            } else {
               p2[ axis ] += 0.5;
            }
         }
      }

/* If all has gone well, create an AST Region (a Box) describing the
   rectangular region of pixel coordinates covered by the pixel array. */
      if( !status ) {
         pixbox = astBox( pixfrm, 1, p1, p2, NULL, " " );

/* Map this box into the FITS world coordinate system. The Mapping is
   specified by "pix2wcs", and the attributes of the resulting axes is
   described by "wcsfrm". */
         wcsbox = astMapRegion( pixbox, pix2wcs, wcsfrm );

/* Create an StcsChan. This is the object that converts (either way)
   between external STC-S descriptions and their corresponding AST Objects.
   Tell it to use the "source" function for obtaining lines of text from
   the disk file. Also tell it to store all warnings generated by the
   conversion for later use. Other attributes of the StcsChan class retain
   their default values. */
         schan = astStcsChan( NULL, NULL, "ReportLevel=3" );

/* Attempt to write out the Region describing the pixel array (in WCS)
   as an STC-S description. Report an error if this fails. */
         if( ! astWrite( schan, wcsbox ) && astOK ) {
            printf( "Failed to convert the Region into an STC-S "
                    "description.\n" );
         }
      }

/* We asked the StcsChan to record any warnings that were generated
   whilst converting the AST Region into a corresponding STC-S description.
   We now see if any such warnings were generated by the earlier call to
   astWrite. */
      warnings = astWarnings( schan );

/* If any warnings were generated, and if no other error has occurred so
   far, display the warnings. */
      if( warnings && !status && astOK ) {
         printf( "\nThe following warnings were issued:\n" );

/* The warnings are stored in an AST KeyMap (a sort of hashmap). Each
   warning message is associated with a key of the form "Warning_1",
   "Warning_2", etc. Loop round successive keys, obtaining a value for
   each key from the warnings KeyMap, and displaying it. */
         iwarn = 1;
         while( astOK ) {
            sprintf( key, "Warning_%d", iwarn++ );
            if( astMapGet0C( warnings, key, &message ) ) {
               printf( "\n- %s\n", message );
            } else {
               break;
            }
         }
      }

/* End the AST Object context. All Objects created since the
   corresponding invocation of astbegin will be annulled automatically. */
      astEnd;

/* Close the disk file. */
      (void) fclose( fd );
   }

/* If an error occurred in the AST library, set the retiurns system
   status non-zero. */
   if( !astOK ) status = 1;
   return status;
}
Exemplo n.º 2
0
int *smf_jsatiles_region( AstRegion *region, smfJSATiling *skytiling,
                          int *ntile, int *status ){

/* Local Variables */
   AstFrameSet *fs;
   AstKeyMap *km;
   AstRegion *region2;
   AstRegion *space_region;
   AstRegion *tregion;
   AstSkyFrame *skyframe;
   char text[ 200 ];
   const char *key;
   double *mesh = NULL;
   double *xmesh;
   double *ymesh;
   int *tiles = NULL;
   int axes[ 2 ];
   int i;
   int ineb;
   int itile2;
   int itile;
   int ix;
   int iy;
   int key_index;
   int lbnd[ 2 ];
   int mapsize;
   int npoint;
   int old_sv;
   int overlap;
   int ubnd[ 2 ];
   int value;
   int xoff[ 4 ] = { -1, 0, 1, 0 };
   int xt;
   int yoff[ 4 ] = { 0, 1, 0, -1 };
   int yt;

/* Initialise */
   *ntile = 0;

/* Check inherited status */
   if( *status != SAI__OK ) return tiles;

/* Start an AST context so that all AST objects created in this function
   are annulled automatically. */
   astBegin;

/* Identify the celestial axes in the Region. */
   atlFindSky( (AstFrame *) region, &skyframe, axes + 1, axes, status );

/* Report an error if no celestial axes were found. */
   if( !skyframe && *status == SAI__OK ) {
      space_region = NULL;
      *status = SAI__ERROR;
      errRep( "", "The current WCS Frame in the supplied Region or "
              "NDF does not include celestial longitude and latitude axes.",
              status );

/* Otherwise, if the Region itself is 2-dimensional, it does not contain
   any other axes, so just use it as is. */
   } else if( astGetI( region, "Naxes" ) == 2 ) {
      space_region = astClone( region );

/* Otherwise, create a new Region by picking the celestial axes from the
   supplied Region. Report an error if a Region cannot be created in this
   way. */
   } else {
      space_region = astPickAxes( region, 2, axes, NULL );
      if( !astIsARegion( space_region ) && *status == SAI__OK ) {
         *status = SAI__ERROR;
         errRep( "", "The  celestial longitude and latitude axes in the "
                 "supplied Region or NDF are not independent of the other "
                 "axes.", status );
      }
   }

/* Create a FrameSet describing the whole sky in which each pixel
   corresponds to a single tile in SMF__JSA_HPX projection. The current
   Frame is ICRS (RA,Dec) and the base Frame is grid coords in which each
   grid pixel corresponds to a single tile. */
   smf_jsatile( -1, skytiling, 0, SMF__JSA_HPX, NULL, &fs, NULL, lbnd, ubnd,
                status );

/* Map the Region using the FrameSet obtained above so that the new Region
   describes offsets in tiles from the lower left tile. If "space_region"
   is a Polygon, ensure that the SimpVertices attribute is set so that the
   simplify method will take non-linearities into account (such as the
   region being split by the RA=12h meridian). */
   astInvert( fs );
   fs = astConvert( space_region, fs, "SKY" );
   if( !fs && *status == SAI__OK ) {
      *status = SAI__ERROR;
      errRep( "", "Cannot convert the supplied Region to ICRS.", status );
      goto L999;
   }

   old_sv = -999;
   if( astIsAPolygon( space_region ) ){
      if( astTest( space_region, "SimpVertices" ) ) {
         old_sv = astGetI( space_region, "SimpVertices" );
      }
      astSetI( space_region, "SimpVertices", 0 );
   }

   region2 = astMapRegion( space_region, fs, fs );

   if( astIsAPolygon( space_region ) ){
      if( old_sv == -999 ) {
         astClear( space_region, "SimpVertices" );
      } else {
         astSetI( space_region, "SimpVertices", old_sv );
      }
   }

/* Get a mesh of all-sky "grid" positions (actually tile X and Y indices)
   covering the region. Since the mesh positions are limited in number
   and placed arbitrarily within the Region, the mesh will identify some,
   but potentially not all, of the tiles that overlap the Region. */
   astGetRegionMesh( region2, 0, 0, 2, &npoint, NULL );
   mesh = astMalloc( 2*npoint*sizeof( *mesh ) );
   astGetRegionMesh( region2, 0, npoint, 2, &npoint, mesh );

/* Find the index of the tile containing each mesh position, and store
   them in a KeyMap using the tile index as the key and "1" (indicating
   the tile overlaps the region) as the value. The KeyMap is sorted by
   age of entry. Neighbouring tiles will be added to this KeyMap later.
   If an entry has a value of zero, it means the tile does not overlap
   the supplied Region. If the value is positive, it means the tile
   does overlap the supplied Region. If the value is negative, it means
   the tile has not yet been tested to see if it overlaps the supplied
   Region. */
   km = astKeyMap( "SortBy=KeyAgeDown" );
   xmesh = mesh;
   ymesh = mesh + npoint;
   for( i = 0; i < npoint && *status == SAI__OK; i++ ) {
      ix = (int)( *(xmesh++) + 0.5 ) - 1;
      iy = (int)( *(ymesh++) + 0.5 ) - 1;
      itile = smf_jsatilexy2i( ix, iy, skytiling, status );
      if (itile != VAL__BADI) {
         sprintf( text, "%d", itile );
         astMapPut0I( km, text, 1, NULL );
      }
   }

/* Starting with the oldest entry in the KeyMap, loop round checking all
   entries, in the order they were added, until all have been checked.
   Checking an entry may cause further entries to be added to the end of
   the KeyMap. */
   key_index = 0;
   mapsize = astMapSize( km );
   while( key_index < mapsize && *status == SAI__OK ) {
      key = astMapKey( km, key_index++ );

/* Convert the key string to an integer tile index. */
      itile = atoi( key );

/* Get the integer value associated with the tile. */
      astMapGet0I( km, key, &value );

/* If the tile associated with the current KeyMap entry has not yet been
   tested for overlap with the requested Region (as shown by the entry
   value being -1), test it now. */
      if( value == -1 ) {

/* Get a Region covering the tile. */
         smf_jsatile( itile, skytiling, 0, SMF__JSA_HPX, NULL, NULL, &tregion,
                      lbnd, ubnd, status );

/* See if this Region overlaps the user supplied region. Set the value of
   the KeyMap entry to +1 or 0 accordingly. */
         overlap = astOverlap( tregion, space_region );
         if( overlap == 0 ) {
            if( *status == SAI__OK ) {
               *status = SAI__ERROR;
               errRep( "", "Cannot align supplied Region with the sky "
                       "tile coordinate system (programming error).",
                       status );
            }
         } else if( overlap == 1 || overlap == 6 ) {
            value = 0;
         } else {
            value = 1;
         }
         astMapPut0I( km, key, value, NULL );
      }

/* Skip the current KeyMap entry if the corresponding tile does not
   overlap the requested Region (as shown by the entry value being zero). */
      if( value == 1 ) {

/* The current tile overlaps the supplied Region, so add the tile index to
   the returned list of tile indices. */
         tiles = astGrow( tiles, ++(*ntile), sizeof( *tiles ) );
         if( *status == SAI__OK ) {
            tiles[ *ntile - 1 ] = itile;

/* Add the adjoining tiles to the end of the KeyMap so that they will be
   tested in their turn, giving them a value of -1 to indicate that they
   have not yet been tested to see if they overlap the supplied Region.
   Ignore adjoining tiles that are already in the keyMap. */
            smf_jsatilei2xy( itile, skytiling, &xt, &yt, NULL, status );
            for( ineb = 0; ineb < 4; ineb++ ) {
               itile2 = smf_jsatilexy2i( xt + xoff[ ineb ], yt + yoff[ ineb ],
                                         skytiling, status );
               if( itile2 != VAL__BADI ) {
                  sprintf( text, "%d", itile2 );
                  if( !astMapHasKey( km, text ) ) {
                     astMapPut0I( km, text, -1, NULL );
                     mapsize++;
                  }
               }
            }
         }
      }
   }

/* Arrive here if an error occurs. */
   L999:;

/* Free resources. */
   mesh = astFree( mesh );

   if( *status != SAI__OK ) {
      tiles = astFree( tiles );
      *ntile = 0;
   }

   astEnd;

   return tiles;
}
Exemplo n.º 3
0
/* Main entry */
void smf_jsadicer( int indf, const char *base, int trim, smf_inst_t instrument,
                   smf_jsaproj_t proj, size_t *ntile, Grp *grp, int *status ){

/* Local Variables: */
   AstBox *box;
   AstFitsChan *fc;
   AstFrame *specfrm = NULL;
   AstFrame *tile_frm = NULL;
   AstFrameSet *iwcs;
   AstFrameSet *tfs = NULL;
   AstFrameSet *tile_wcs;
   AstMapping *ndf_map = NULL;
   AstMapping *p2pmap = NULL;
   AstMapping *specmap = NULL;
   AstMapping *tile_map = NULL;
   AstRegion *region;
   Grp *grpt = NULL;
   char *path;
   char dtype[ NDF__SZFTP + 1 ];
   char jsatile_comment[45];
   char type[ NDF__SZTYP + 1 ];
   const char *dom = NULL;
   const char *keyword;
   const char *latsys = NULL;
   const char *lonsys = NULL;
   double *pd;
   double dlbnd[3];
   double dubnd[3];
   double gcen[3];
   double lbnd_in[3];
   double lbnd_out[3];
   double ubnd_in[3];
   double ubnd_out[3];
   float *pf;
   int *created_tiles = NULL;
   int *tiles;
   int axlat;
   int axlon;
   int axspec;
   int bbox[ 6 ];
   int i;
   int ifrm;
   int igrid;
   int indfo;
   int indfs;
   int indfx;
   int inperm[3];
   int ipixel;
   int ishpx;
   int isxph;
   int itile;
   int ix;
   int iy;
   int iz;
   int junk;
   int latax = -1;
   int lbnd[3];
   int lbnd_tile[ 3 ];
   int lbndx[ NDF__MXDIM ];
   int lonax = -1;
   int nbase;
   int ndim;
   int ndimx;
   int nfrm;
   int nsig;
   int ntiles;
   int olbnd[ 3 ];
   int oubnd[ 3 ];
   int outperm[ 3 ];
   int place;
   int qual;
   int tile_index;
   int tile_lbnd[2];
   int tile_ubnd[2];
   int ubnd[3];
   int ubnd_tile[ 3 ];
   int ubndx[ NDF__MXDIM ];
   int var;
   size_t iext;
   size_t size;
   smfJSATiling tiling;
   unsigned char *ipq = NULL;
   void *ipd = NULL;
   void *ipv = NULL;

/* Initialise */
   *ntile = 0;

/* Check inherited status */
   if( *status != SAI__OK ) return;

/* Begin an AST context. */
   astBegin;

/* Begin an NDF context. */
   ndfBegin();

/* Note the used length of the supplied base string. If it ends with
   ".sdf", reduce it by 4. */
   nbase = astChrLen( base );
   if( !strcmp( base + nbase - 4, ".sdf" ) ) nbase -= 4;

/* Allocate a buffer large enough to hold the full path for an output NDF. */
   path = astMalloc( nbase + 25 );

/* Get the WCS from the NDF. */
   kpg1Gtwcs( indf, &iwcs, status );

/* Note if the NDF projection is HPX or XPH. */
   ishpx = astChrMatch( astGetC( iwcs, "Projection" ), "HEALPix" );
   isxph = astChrMatch( astGetC( iwcs, "Projection" ), "polar HEALPix" );

/* Report an error if the NDFs projection is neither of these. */
   if( !ishpx && !isxph && *status == SAI__OK ) {
      ndfMsg( "N", indf );
      *status = SAI__ERROR;
      errRep( "", "The input NDF (^N) does not appear to be gridded "
              "on the JSA all-sky pixel grid.", status );
   }

/* Get the bounds of the NDF in pixel indices and the the corresponding
   double precision GRID bounds (reduce the size of the grid by a small
   amount to avoid problems with tiles that are on the edge of the valid sky
   regions - astMapRegion can report an error for such tiles). Also store
   the GRID coords of the centre. Also count the number of significant
   pixel axes. */
   ndfBound( indf, 3, lbnd, ubnd, &ndim, status );
   nsig = 0;
   for( i = 0; i < ndim; i++ ) {
      dlbnd[ i ] = 0.5 + 0.1;
      dubnd[ i ] = ubnd[ i ] - lbnd[ i ]  + 1.5 - 0.1;
      gcen[ i ] = 0.5*( dlbnd[ i ] + dubnd[ i ] );
      if( ubnd[ i ] > lbnd[ i ] ) nsig++;
   }

/* Find the one-based indices of the RA, Dec and spectral axes in the
   current Frame of the NDF. */
   axlon = 0;
   if( astGetI( iwcs, "IsLonAxis(1)" ) ) {
      axlon = 1;
      lonsys = astGetC( iwcs, "System(1)" );
   } else if( astGetI( iwcs, "IsLonAxis(2)" ) ) {
      axlon = 2;
      lonsys = astGetC( iwcs, "System(2)" );
   } else if( ndim == 3 && astGetI( iwcs, "IsLonAxis(3)" ) ) {
      axlon = 3;
      lonsys = astGetC( iwcs, "System(3)" );
   } else if( *status == SAI__OK ) {
      *status = SAI__ERROR;
      errRep( "", "smf_jsadicer: Cannot find the longitude axis in the "
              "input NDF.", status );
   }

   axlat = 0;
   if( astGetI( iwcs, "IsLatAxis(1)" ) ) {
      axlat = 1;
      latsys = astGetC( iwcs, "System(1)" );
   } else if( astGetI( iwcs, "IsLatAxis(2)" ) ) {
      axlat = 2;
      latsys = astGetC( iwcs, "System(2)" );
   } else if( ndim == 3 && astGetI( iwcs, "IsLatAxis(3)" ) ) {
      axlat = 3;
      latsys = astGetC( iwcs, "System(3)" );
   } else if( *status == SAI__OK ) {
      *status = SAI__ERROR;
      errRep( "", "smf_jsadicer: Cannot find the latitude axis in the "
              "input NDF.", status );
   }

   axspec = 6 - axlon - axlat;

/* Report an error if the spatial axes are not ICRS RA and Dec. */
   if( ( lonsys && strcmp( lonsys, "ICRS" ) ) ||
       ( latsys && strcmp( latsys, "ICRS" ) ) ) {
      if( *status == SAI__OK ) {
         *status = SAI__ERROR;
         ndfMsg( "N", indf );
         errRep( "", "smf_jsadicer: The spatial axes in '^N' are not "
                 "ICRS RA and Dec.", status );
      }
   }

/* Create a Box describing the region covered by the NDF pixel grid in
   GRID coords. */
   box = astBox( astGetFrame( iwcs, AST__BASE ), 1, dlbnd, dubnd,
                 AST__NULL, " " );

/* Map this Box into the current WCS Frame of the NDF. */
   region = astMapRegion( box, iwcs, iwcs );

/* If no instrument was specified, we will determine the instrument from
   the contexts of the FITS extension. Copy the NDF FITS extension to a
   FitsChan. Annul the error if the NDF no FITS extension. */
   if( instrument == SMF__INST_NONE && *status == SAI__OK ) {
      kpgGtfts( indf, &fc, status );
      if( *status == KPG__NOFTS ) {
         errAnnul( status );
         fc = NULL;
      }
   } else {
      fc = NULL;
   }

/* Get the parameters of the required tiling scheme. */
   smf_jsainstrument( NULL, fc, instrument, &tiling, status );

/* Get a list of the JSA tiles touched by the supplied NDF. */
   tiles = smf_jsatiles_region( region, &tiling, &ntiles, status );
   if( ntiles == 0 && *status == SAI__OK ) {
      *status = SAI__ERROR;
      errRep( "", "smf_jsadicer: No JSA tiles found touching supplied NDF "
              "(programming error).", status );
   }

/* Does the input NDF have a Variance component? */
   ndfState( indf, "Variance", &var, status );

/* Does the input NDF have a Quality component? */
   ndfState( indf, "Quality", &qual, status );

/* Decide on the data type to use: _REAL or _DOUBLE. */
   ndfMtype( "_REAL,_DOUBLE", indf, indf, "Data", type, sizeof(type), dtype,
             sizeof(dtype), status );

/* Tell the user what is happening. */
   msgBlank( status );
   msgOutf( "", "Dicing %s into JSA tiles:", status,
            ( nsig == 2 ) ? "map" : "cube" );

/* Loop round all tiles that overlap the supplied NDF. */
   for( itile = 0; itile < ntiles && *status == SAI__OK; itile++ ) {
      tile_index = tiles[ itile ];

/* Get the spatial pixel bounds of the current tile within the requested
   JSA all-sky projection. Also get the (2D) WCS FrameSet for the tile. */
      smf_jsatile( tile_index, &tiling, 0, proj, NULL, &tile_wcs, NULL,
                   tile_lbnd, tile_ubnd, status );

/* Extract the tile pixel->WCS mapping and WCS Frame. We know the indices
   of the required Frames because they are hard-wired in smf_jsatile. */
      tile_map = astGetMapping( tile_wcs, 3, 2 );
      tile_frm = astGetFrame( tile_wcs, 2 );

/* Find the indices of the grid and pixel frames in the input NDF. */
      ipixel = -1;
      igrid = astGetI( iwcs, "Base" );
      nfrm = astGetI( iwcs, "NFrame" );
      for( ifrm = 0; ifrm < nfrm; ifrm++ ) {
         dom = astGetC( astGetFrame( iwcs, ifrm + 1 ), "Domain" );
         if( astChrMatch( dom, "PIXEL" ) ) ipixel = ifrm + 1;
      }

/* If required, extract the pixel->spectral mapping and spectral frame in
   the input NDF, and add it in parallel with the above tile mapping. */
      if( ndim == 3 ) {
         astSetI( iwcs, "Base", ipixel );
         tfs = atlFrameSetSplit( iwcs, "DSBSPECTRUM SPECTRUM", NULL,
                                 NULL, status );
         astSetI( iwcs, "Base", igrid );
         if( tfs ) {
            specmap = astGetMapping( tfs, AST__BASE, AST__CURRENT );
            specfrm = astGetFrame( tfs, AST__CURRENT );
         } else if( *status == SAI__OK ) {
            *status = SAI__ERROR;
            ndfMsg( "N", indf );
            errRep( "", "smf_jsadicer: Cannot find the spectral axis "
                    "in '^N'.", status );
         }

         tile_map = (AstMapping *) astCmpMap( tile_map, specmap, 0, " " );
         tile_frm = (AstFrame *) astCmpFrame( tile_frm, specfrm, " " );
      }

/* Ensure the Epoch is inherited form the input NDF. */
      astSetD( tile_frm, "Epoch", astGetD( iwcs, "Epoch" ) );

/* Currently tile axis 1 is RA, axis 2 is Dec and axis 3 (if present) is
   spectral. Append a PermMap that re-orders these tile WCS axes to match
   those of the NDF. */
      outperm[ axlon - 1 ] = 1;
      outperm[ axlat - 1 ] = 2;
      outperm[ axspec - 1 ] = 3;
      inperm[ 0 ] = axlon;
      inperm[ 1 ] = axlat;
      inperm[ 2 ] = axspec;
      tile_map = (AstMapping *) astCmpMap( tile_map, astPermMap( ndim, inperm,
                                                                 ndim, outperm,
                                                                 NULL, " " ),
                                           1, " " );
      tile_map = astSimplify( tile_map );

/* Also re-order the WCS axes in the tile frame. */
      astPermAxes( tile_frm, outperm );

/* We want the zero-based indicies of the input pixel axes corresponding
   to ra, dec and spectral. So find the indicies of the pixel axes in the
   supplied NDF that are most closely aligned with each WCS axis. */
      atlPairAxes( iwcs, NULL, gcen, NULL, inperm, status );
      if( inperm[ 0 ] == axlon ) {
         lonax = 0;
      } else if( inperm[ 1 ] == axlon ) {
         lonax = 1;
      } else {
         lonax = 2;
      }
      if( inperm[ 0 ] == axlat ) {
         latax = 0;
      } else if( inperm[ 1 ] == axlat ) {
         latax = 1;
      } else {
         latax = 2;
      }

/* To get the mapping from pixel coords in the input NDF to pixel coords
   in the output NDF, we invert the above mapping so that it goes from WCS
   to pixel, and append it to the end of the NDF pixel->WCS mapping. */
      ndf_map = astGetMapping( iwcs, ipixel, AST__CURRENT );
      astInvert( tile_map );
      p2pmap = (AstMapping *) astCmpMap( ndf_map, tile_map, 1, " " );
      p2pmap = astSimplify( p2pmap );
      astInvert( tile_map );

/* Show the bounds of the tile within the input NDF. */
      msgOutiff( MSG__DEBUG, "", "   tile %d has bounds (%d:%d,%d:%d) "
                 "within the output NDF.", status, tile_index,
                 tile_lbnd[ 0 ], tile_ubnd[ 0 ], tile_lbnd[ 1 ],
                 tile_ubnd[ 1 ] );

/* Next job is to find the pixel bounds of the output NDF to create
   which will hold data for the current tile. First map the pixel bounds
   of the whole tile from output to input. */
      lbnd_in[ 0 ] = tile_lbnd[ 0 ] - 0.5;
      lbnd_in[ 1 ] = tile_lbnd[ 1 ] - 0.5;
      lbnd_in[ 2 ] = lbnd[ 2 ] - 0.5;
      ubnd_in[ 0 ] = tile_ubnd[ 0 ] - 0.5;
      ubnd_in[ 1 ] = tile_ubnd[ 1 ] - 0.5;
      ubnd_in[ 2 ] = ubnd[ 2 ] - 0.5;

      astMapBox( p2pmap, lbnd_in, ubnd_in, 0, 1, lbnd_out + 0,
                 ubnd_out + 0, NULL, NULL );
      astMapBox( p2pmap, lbnd_in, ubnd_in, 0, 2, lbnd_out + 1,
                 ubnd_out + 1, NULL, NULL );
      if( ndim == 3 ) astMapBox( p2pmap, lbnd_in, ubnd_in, 0, 3,
                                 lbnd_out + 2, ubnd_out + 2, NULL,
                                 NULL );


      lbnd_tile[ 0 ] = floor( lbnd_out[ 0 ] ) + 1;
      lbnd_tile[ 1 ] = floor( lbnd_out[ 1 ] ) + 1;
      lbnd_tile[ 2 ] = floor( lbnd_out[ 2 ] ) + 1;
      ubnd_tile[ 0 ] = floor( ubnd_out[ 0 ] ) + 1;
      ubnd_tile[ 1 ] = floor( ubnd_out[ 1 ] ) + 1;
      ubnd_tile[ 2 ] = floor( ubnd_out[ 2 ] ) + 1;

/* Show the bounds of the tile within the input NDF. */
      msgOutiff( MSG__DEBUG, "", "   tile %d has bounds (%d:%d,%d:%d) "
                 "within the input NDF.", status, tile_index,
                 lbnd_tile[ 0 ], ubnd_tile[ 0 ], lbnd_tile[ 1 ],
                 ubnd_tile[ 1 ] );

/* If required, trim the bounds to the extent of the input NDF. */
      if( trim ) {
         if( lbnd_tile[ 0 ] < lbnd[ 0 ] ) lbnd_tile[ 0 ] = lbnd[ 0 ];
         if( lbnd_tile[ 1 ] < lbnd[ 1 ] ) lbnd_tile[ 1 ] = lbnd[ 1 ];
         if( lbnd_tile[ 2 ] < lbnd[ 2 ] ) lbnd_tile[ 2 ] = lbnd[ 2 ];
         if( ubnd_tile[ 0 ] > ubnd[ 0 ] ) ubnd_tile[ 0 ] = ubnd[ 0 ];
         if( ubnd_tile[ 1 ] > ubnd[ 1 ] ) ubnd_tile[ 1 ] = ubnd[ 1 ];
         if( ubnd_tile[ 2 ] > ubnd[ 2 ] ) ubnd_tile[ 2 ] = ubnd[ 2 ];
      }

/* Check there is some overlap. */
      if( lbnd_tile[ 0 ] <= ubnd_tile[ 0 ] &&
          lbnd_tile[ 1 ] <= ubnd_tile[ 1 ] &&
          lbnd_tile[ 2 ] <= ubnd_tile[ 2 ] ){

/* Now need to check if this section of the input NDF contains any good
   values. We also find the bounding box of the good values (within the
   input pixel coordinate system). So first obtain and map the required
   section of the input NDF. */
         ndfSect( indf, ndim, lbnd_tile, ubnd_tile, &indfs, status );
         ndfMap( indfs, "Data", type, "Read", &ipd, &junk, status );
         if( var ) ndfMap( indfs, "Variance", type, "Read", &ipv, &junk, status );
         if( qual ) ndfMap( indfs, "Quality", "_UBYTE", "Read", (void **) &ipq,
                            &junk, status );

/* Initialise the pixel bounds (within the input NDF) of the box holding
   good data values for the current tile. */
         bbox[ 0 ] = INT_MAX;
         bbox[ 1 ] = INT_MAX;
         bbox[ 2 ] = INT_MAX;
         bbox[ 3 ] = -INT_MAX;
         bbox[ 4 ] = -INT_MAX;
         bbox[ 5 ] = -INT_MAX;

/* Loop round all pixels in the section. */
         if( *status == SAI__OK ) {
            if( !strcmp( type, "_REAL" ) ) {
               pf = (float *) ipd;
               for( iz = lbnd_tile[ 2 ]; iz <= ubnd_tile[ 2 ]; iz++ ) {
                  for( iy = lbnd_tile[ 1 ]; iy <= ubnd_tile[ 1 ]; iy++ ) {
                     for( ix = lbnd_tile[ 0 ]; ix <= ubnd_tile[ 0 ]; ix++ ) {
                        if( *(pf++) != VAL__BADR ) {
                           if( ix < bbox[ 0 ] ) bbox[ 0 ] = ix;
                           if( iy < bbox[ 1 ] ) bbox[ 1 ] = iy;
                           if( iz < bbox[ 2 ] ) bbox[ 2 ] = iz;
                           if( ix > bbox[ 3 ] ) bbox[ 3 ] = ix;
                           if( iy > bbox[ 4 ] ) bbox[ 4 ] = iy;
                           if( iz > bbox[ 5 ] ) bbox[ 5 ] = iz;
                        }
                     }
                  }
               }
            } else {
               pd = (double *) ipd;
               for( iz = lbnd_tile[ 2 ]; iz <= ubnd_tile[ 2 ]; iz++ ) {
                  for( iy = lbnd_tile[ 1 ]; iy <= ubnd_tile[ 1 ]; iy++ ) {
                     for( ix = lbnd_tile[ 0 ]; ix <= ubnd_tile[ 0 ]; ix++ ) {
                        if( *(pd++) != VAL__BADD ) {
                           if( ix < bbox[ 0 ] ) bbox[ 0 ] = ix;
                           if( iy < bbox[ 1 ] ) bbox[ 1 ] = iy;
                           if( iz < bbox[ 2 ] ) bbox[ 2 ] = iz;
                           if( ix > bbox[ 3 ] ) bbox[ 3 ] = ix;
                           if( iy > bbox[ 4 ] ) bbox[ 4 ] = iy;
                           if( iz > bbox[ 5 ] ) bbox[ 5 ] = iz;
                        }
                     }
                  }
               }
            }

/* Skip empty tiles. */
            if( bbox[ 0 ] != INT_MAX ) {
               msgOutf( "", "   tile %d", status, tile_index );

/* If required, trim the bounds to the edges of the bounding box. */
               if( trim >= 2 ) {
                  olbnd[ 0 ] = bbox[ 0 ];
                  olbnd[ 1 ] = bbox[ 1 ];
                  olbnd[ 2 ] = bbox[ 2 ];
                  oubnd[ 0 ] = bbox[ 3 ];
                  oubnd[ 1 ] = bbox[ 4 ];
                  oubnd[ 2 ] = bbox[ 5 ];
               } else {
                  olbnd[ 0 ] = lbnd_tile[ 0 ];
                  olbnd[ 1 ] = lbnd_tile[ 1 ];
                  olbnd[ 2 ] = lbnd_tile[ 2 ];
                  oubnd[ 0 ] = ubnd_tile[ 0 ];
                  oubnd[ 1 ] = ubnd_tile[ 1 ];
                  oubnd[ 2 ] = ubnd_tile[ 2 ];
               }

/* Modify these pixel bounds so that they refer to the output NDF. */
               lbnd_in[ 0 ] = olbnd[ 0 ] - 0.5;
               lbnd_in[ 1 ] = olbnd[ 1 ] - 0.5;
               lbnd_in[ 2 ] = olbnd[ 2 ] - 0.5;
               ubnd_in[ 0 ] = oubnd[ 0 ] - 0.5;
               ubnd_in[ 1 ] = oubnd[ 1 ] - 0.5;
               ubnd_in[ 2 ] = oubnd[ 2 ] - 0.5;

               astMapBox( p2pmap, lbnd_in, ubnd_in, 1, 1, lbnd_out + 0,
                          ubnd_out + 0, NULL, NULL );
               astMapBox( p2pmap, lbnd_in, ubnd_in, 1, 2, lbnd_out + 1,
                          ubnd_out + 1, NULL, NULL );
               if( ndim == 3 ) astMapBox( p2pmap, lbnd_in, ubnd_in, 1, 3,
                                          lbnd_out + 2, ubnd_out + 2, NULL,
                                          NULL );

               olbnd[ 0 ] = floor( lbnd_out[ 0 ] ) + 1;
               olbnd[ 1 ] = floor( lbnd_out[ 1 ] ) + 1;
               olbnd[ 2 ] = floor( lbnd_out[ 2 ] ) + 1;
               oubnd[ 0 ] = floor( ubnd_out[ 0 ] ) + 1;
               oubnd[ 1 ] = floor( ubnd_out[ 1 ] ) + 1;
               oubnd[ 2 ] = floor( ubnd_out[ 2 ] ) + 1;

/* Get the full path to the output NDF for the current tile, and create an
   NDF placeholder for it. */
               sprintf( path, "%.*s_%d", nbase, base, tile_index );
               ndfPlace( NULL, path, &place, status );

/* Create a new output NDF by copying the meta-data from the input NDF
   section. */
               ndfScopy( indfs, "Units", &place, &indfo, status );

/* Set the pixel bounds of the output NDF to the values found above and copy
   the input data for the current tile into it. */
               smf1_jsadicer( indfo, olbnd, oubnd, tile_map, tile_frm, p2pmap,
                              ipd, ipv, ipq, status );

/* Add the name of this output NDF to the group holding the names of the
   output NDFs that have actually been created. */
               if( grp ) grpPut1( grp, path, 0, status );

/* Add a TILENUM header to the output FITS extension. */
               kpgGtfts( indfo, &fc, status );
               if( *status == KPG__NOFTS ) {
                  errAnnul( status );
                  fc = astFitsChan( NULL, NULL, " " );

/* If the last card is "END", remove it. */
               } else {
                  astSetI( fc, "Card", astGetI( fc, "NCARD" ) );
                  keyword = astGetC( fc, "CardName" );
                  if( keyword && !strcmp( keyword, "END" ) ) astDelFits( fc );
               }

               one_snprintf(jsatile_comment, 45, "JSA all-sky tile index (Nside=%i)",
                            status, tiling.ntpf);
               atlPtfti( fc, "TILENUM", tile_index, jsatile_comment, status );
               kpgPtfts( indfo, fc, status );
               fc = astAnnul( fc );

/* Now store an STC-S polygon that describes the shortest boundary
   enclosing the good data in the output NDF, and store it as an NDF extension. */
               kpgPutOutline( indfo, 0.5, 1, status );

/* We now reshape any extension NDFs contained within the output NDF to
   have the same spatial bounds as the main NDF (but only for extension
   NDFs that originally have the same spatial bounds as the supplied NDF).
   Get a group containing paths to all extension NDFs in the output NDF. */
               ndgMoreg( indfo, &grpt, &size, status );

/* Loop round each output extension NDF. */
               for( iext = 1; iext <= size && *status == SAI__OK; iext++ ) {
                  ndgNdfas( grpt, iext, "Update", &indfx, status );

/* Get its bounds. */
                  ndfBound( indfx, NDF__MXDIM, lbndx, ubndx, &ndimx, status );

/* See if this extension NDF has the same bounds on the spatial axes as
   the supplied NDF. */
                  if( ndimx > 1 && lbndx[ lonax ] == lbnd[ lonax ] &&
                                   lbndx[ latax ] == lbnd[ latax ] &&
                                   ubndx[ lonax ] == ubnd[ lonax ] &&
                                   ubndx[ latax ] == ubnd[ latax ] ) {

/* If so, change the bounds of the output extension NDF so that they are
   the same as the main NDF on the spatial axes, and map the original
   contents of the NDF onto the new pixel grid. */
                     smf1_jsadicer( indfx, olbnd, oubnd, tile_map, tile_frm, p2pmap,
                                    NULL, NULL, NULL, status );
                  }

/* Annul the extension NDF identifier. */
                  ndfAnnul( &indfx, status );
               }

/* Free resources associated with the current tile. */
               grpDelet( &grpt, status );
               ndfAnnul( &indfo, status );

/* Issue warnings about empty tiles. */
            } else {
               msgOutiff( MSG__VERB, "", "   tile %d is empty and so will not be "
                          "created", status, tile_index );
            }
         }

/* Free the section of the input NDF. */
         ndfAnnul( &indfs, status );

/* Append the index of this tile in the list of tiles to be created. */
         created_tiles = astGrow( created_tiles, ++(*ntile),
                                  sizeof( *created_tiles ) );
         if( *status == SAI__OK ) created_tiles[ *ntile - 1 ] = tile_index;

      } else {
         msgOutiff( MSG__DEBUG, "", "   Tile %d does not overlap the input "
                    "NDF after trimming.", status, tile_index );
      }
   }
   msgBlank( status );

/* Write the indicies of the created tiles out to a parameter. */
   if( *ntile ) parPut1i( "JSATILELIST", *ntile, created_tiles, status );

/* Free resources. */
   created_tiles = astFree( created_tiles );
   tiles = astFree( tiles );
   path = astFree( path );

/* End the NDF context. */
   ndfEnd( status );

/* End the AST context. */
   astEnd;

}
Exemplo n.º 4
0
void smurf_jsatileinfo( int *status ) {

/* Local Variables */
   AstCmpRegion *overlap;
   AstFitsChan *fc;
   AstFrameSet *fs;
   AstObject *obj;
   AstRegion *region;
   AstRegion *target;
   HDSLoc *cloc = NULL;
   HDSLoc *xloc = NULL;
   char *jcmt_tiles;
   char *tilendf = NULL;
   char text[ 200 ];
   double dec[ 8 ];
   double dist;
   double dlbnd[ 2 ];
   double dubnd[ 2 ];
   double gx[ 8 ];
   double gy[ 8 ];
   double maxdist;
   double norm_radec[2];
   double point1[ 2 ];
   double point2[ 2 ];
   double ra[ 8 ];
   double ra0;
   double dec0;
   int *ipntr;
   int axes[ 2 ];
   int create;
   int dirlen;
   int el;
   int exists;
   int flag;
   int i;
   int indf1;
   int indf2;
   int indf3;
   int itile;
   int iv;
   int jtile;
   int lbnd[ 2 ];
   int local_origin;
   int nc;
   int place;
   int tlbnd[ 2 ];
   int tubnd[ 2 ];
   int ubnd[ 2 ];
   smf_jsaproj_t proj;
   int xt;
   int yt;
   smfJSATiling skytiling;
   void *pntr;

/* Check inherited status */
   if( *status != SAI__OK ) return;

/* Start a new AST context. */
   astBegin;

/* Get the instrument to use abnd get the parameters describing the
   layout of its JSA tiles. */
   smf_jsainstrument( "INSTRUMENT", NULL, SMF__INST_NONE, &skytiling,
                      status );

/* Return the maximum tile index. */
   parPut0i( "MAXTILE", skytiling.ntiles - 1, status );

/* Abort if an error has occurred. */
   if( *status != SAI__OK ) goto L999;

/* Decide what sort of projection to use. */
   parChoic( "PROJ", "HPX", "HPX,HPX12,XPHN,XPHS", 1, text, sizeof(text),
             status );
   proj = smf_jsaproj_fromstr( text, 1, status );

/* If required, create an all-sky NDF in which each pixel covers the area
   of a single tile, and holds the integer tile index. The NDF has an
   initial size of 1x1 pixels, but is expanded later to the required size. */
   lbnd[ 0 ] = ubnd[ 0 ] = lbnd[ 1 ] = ubnd[ 1 ] = 1;
   ndfCreat( "ALLSKY", "_INTEGER", 2, lbnd, ubnd, &indf3, status );

/* If a null (!) value was supplied for parameter ALLSKY, annull the
   error and pass on. */
   if( *status == PAR__NULL ) {
      errAnnul( status );

/* Otherwise, create a FrameSet describing the whole sky in which each
   pixel corresponds to a single tile. */
   } else {
      smf_jsatile( -1, &skytiling, 0, proj, NULL, &fs, NULL, lbnd, ubnd,
                   status );

/* Change the bounds of the output NDF. */
      ndfSbnd( 2, lbnd, ubnd, indf3, status );

/* Store the FrameSet in the NDF. */
      ndfPtwcs( fs, indf3, status );

/* Map the data array. */
      ndfMap( indf3, "Data", "_INTEGER", "WRITE/BAD", (void **) &ipntr, &el,
              status );

/* Create all-sky map using XPH projection. */
      if( *status == SAI__OK ) {

/* Loop round every tile index. */
         for( jtile = 0; jtile < skytiling.ntiles; jtile++ ) {

/* Get the zero-based (x,y) indices of the tile within an HPX projection.
   This flips the bottom left half-facet up to the top right. */
            smf_jsatilei2xy( jtile, &skytiling, &xt, &yt, NULL, status );

/* Convert these HPX indices to the corresponding indices within the
   required projection. Note, the lower left facet is split by the above
   call to smf_jsatilei2xy tile (i.e. (xt,yt) indices are *not* in the
   "raw" mode). For instance, (0,0) is not a valid tile. */
            smf_jsatilexyconv( &skytiling, proj, xt, yt, 0, &xt, &yt, status );

/* Get the vector index of the corresponding element of the all-sky NDF. */
            if( proj == SMF__JSA_HPX || proj == SMF__JSA_HPX12 ) {
               iv = xt + 5*skytiling.ntpf*yt;
            } else {
               iv = xt + 4*skytiling.ntpf*yt;
            }

/* Report an error if this element has already been assigned a tile
   index. Otherwise, store the tile index. */
            if( ipntr[ iv ] == VAL__BADI ) {
               ipntr[ iv ] = jtile;
            } else if( *status == SAI__OK ) {
               *status = SAI__ERROR;
               errRepf( "", "%s projection assigns multiple tiles to "
                        "pixel (%d,%d).", status, text, xt, yt );
               break;
            }
         }
      }

/* Store NDF title. */
      sprintf( text, "JSA tile indices for %s data", skytiling.name );
      ndfCput( text, indf3, "TITLE", status );

/* Store the instrument as a component in the SMURF extension. */
      ndfXnew( indf3, "SMURF", "INSTRUMENT", 0, 0, &xloc, status );
      ndfXpt0c( skytiling.name, indf3, "SMURF", "INSTRUMENT", status );
      datAnnul( &xloc, status );

/* Close the NDF. */
      ndfAnnul( &indf3, status );
   }

/* Abort if an error has occurred. */
   if( *status != SAI__OK ) goto L999;

/* Get the zero-based index of the required tile. If a null value is
   supplied, annull the error and skip to the end. */
   parGdr0i( "ITILE", 0, 0, skytiling.ntiles - 1, 0, &itile, status );
   if( *status == PAR__NULL ) {
       errAnnul( status );
       goto L999;
   }

/* See if the pixel origin is to be at the centre of the tile. */
   parGet0l( "LOCAL", &local_origin, status );

/* Display the tile number. */
   msgBlank( status );
   msgSeti( "ITILE", itile );
   msgSeti( "MAXTILE", skytiling.ntiles - 1);
   msgOut( " ", "   Tile ^ITILE (from 0 to ^MAXTILE):", status );

/* Get the FITS header, FrameSet and Region defining the tile, and the tile
   bounds in pixel indices. */
   smf_jsatile( itile, &skytiling, local_origin,  proj, &fc, &fs, &region,
                lbnd, ubnd, status );

/* Write the FITS headers out to a file, annulling the error if the
   header is not required. */
   if( *status == SAI__OK ) {
      atlDumpFits( "HEADER", fc, status );
      if( *status == PAR__NULL ) errAnnul( status );
   }

/* If required, write the Region out to a text file. */
   if( *status == SAI__OK ) {
      atlCreat( "REGION", (AstObject *) region, status );
      if( *status == PAR__NULL ) errAnnul( status );
   }

/* Store the lower and upper pixel bounds of the tile. */
   parPut1i( "LBND", 2, lbnd, status );
   parPut1i( "UBND", 2, ubnd, status );

/* Display pixel bounds on the screen. */
   msgSeti( "XL", lbnd[ 0 ] );
   msgSeti( "XU", ubnd[ 0 ] );
   msgSeti( "YL", lbnd[ 1 ] );
   msgSeti( "YU", ubnd[ 1 ] );
   msgOut( " ", "      Pixel bounds: (^XL:^XU,^YL:^YU)", status );

/* Get the RA,Dec at the tile centre. */
   if( astTest( fs, "SkyRef" ) ) {
      ra0 = astGetD( fs, "SkyRef(1)" );
      dec0 = astGetD( fs, "SkyRef(2)" );

/* Format the central RA and Dec. and display. Call astNorm on the
   coordinates provided that the frame set has the correct number of
   axes (which it should as it comes from smf_jsatile). */
      norm_radec[0] = ra0;
      norm_radec[1] = dec0;
      if (astGetI(fs, "Naxes") == 2) astNorm(fs, norm_radec);
      msgSetc( "RACEN",  astFormat( fs, 1, norm_radec[ 0 ] ));
      msgSetc( "DECCEN",  astFormat( fs, 2, norm_radec[ 1 ] ));
      msgOut( " ", "      Centre (ICRS): RA=^RACEN DEC=^DECCEN", status );

/* Transform a collection of points on the edge of the region (corners and
   side mid-points) from GRID coords to RA,Dec. */
      point1[ 0 ] = 0.5;
      point1[ 1 ] = 0.5;
      point2[ 0 ] = ubnd[ 0 ] - lbnd[ 0 ] + 1;
      point2[ 1 ] = ubnd[ 1 ] - lbnd[ 1 ] + 1;

      gx[ 0 ] = point1[ 0 ];         /* Bottom left */
      gy[ 0 ] = point1[ 1 ];

      gx[ 1 ] = point1[ 0 ];         /* Centre left */
      gy[ 1 ] = gy[ 0 ];

      gx[ 2 ] = point1[ 0 ];         /* Top left */
      gy[ 2 ] = point2[ 1 ];

      gx[ 3 ] = gx[ 0 ];             /* Top centre */
      gy[ 3 ] = point2[ 1 ];

      gx[ 4 ] = point2[ 0 ];         /* Top right */
      gy[ 4 ] = point2[ 1 ];

      gx[ 5 ] = point2[ 0 ];         /* Centre right */
      gy[ 5 ] = gy[ 0 ];

      gx[ 6 ] = point2[ 0 ];         /* Bottom right */
      gy[ 6 ] = point1[ 1 ];

      gx[ 7 ] = gx[ 0 ];             /* Bottom centre */
      gy[ 7 ] = point1[ 1 ];

      astTran2( fs, 8, gx, gy, 1, ra, dec );

/* Find the arc-distance from the centre to the furthest point from the
   centre. */
      point1[ 0 ] = ra0;
      point1[ 1 ] = dec0;
      maxdist = -1.0;

      for( i = 1; i < 8; i++ ) {
         if( ra[ i ] != AST__BAD && dec[ i ] != AST__BAD ) {
            point2[ 0 ] = ra[ i ];
            point2[ 1 ] = dec[ i ];
            dist = astDistance( fs, point1, point2 );
            if( dist > maxdist ) maxdist = dist;
         }
      }

/* Convert from radius to diameter. */
      maxdist *= 2.0;

/* Format this size as a dec value (i.e. arc-distance) and display it. */
      if( maxdist > 0.0 ) {
         msgSetc( "SIZE",  astFormat( fs, 2, maxdist ) );
         msgOut( " ", "      Size: ^SIZE", status );
      } else {
         maxdist = AST__BAD;
         msgOut( " ", "      Size: <unknown>", status );
      }

/* If a discontinuity passes through the tile, the centre and size may be
   unknown. */
   } else {
      ra0 = AST__BAD;
      dec0 = AST__BAD;
      maxdist = AST__BAD;
      msgOut( " ", "      Centre (ICRS): RA=<unknown> DEC=<unknown>", status );
      msgOut( " ", "      Size: <unknown>", status );
   }

/* Write the tile centre ra and dec in radians to the output parameters. */
   parPut0d( "RACEN", norm_radec[ 0 ], status );
   parPut0d( "DECCEN", norm_radec[ 1 ], status );

/* Write the size to the output parameter as radians. */
   parPut0d( "SIZE", maxdist, status );

/* Get the translation of the environment variable JSA_TILE_DIR. */
   jcmt_tiles = getenv( "JSA_TILE_DIR" );

/* Initialise the path to the tile's NDF to hold the root directory.
   Use the current working directory if JSA_TILE_DIR is undefined. */
   if( jcmt_tiles ) {
      nc = 0;
      tilendf = astAppendString( tilendf, &nc, jcmt_tiles );

   } else {

      nc = 512;
      jcmt_tiles = astMalloc( nc );

      while( !getcwd( jcmt_tiles, nc ) ) {
         nc *= 2;
         jcmt_tiles = astRealloc( jcmt_tiles, nc );
      }

      nc = 0;
      tilendf = astAppendString( tilendf, &nc, jcmt_tiles );
      jcmt_tiles = astFree( jcmt_tiles );
   }

/* Complete the path to the tile's NDF. */
   tilendf = astAppendString( tilendf, &nc, "/" );
   tilendf = astAppendString( tilendf, &nc, skytiling.subdir );
   dirlen = nc;
   sprintf( text, "/tile_%d.sdf", itile );
   tilendf = astAppendString( tilendf, &nc, text );

/* Write it to the output parameter. */
   parPut0c( "TILENDF", tilendf, status );

/* See if the NDF exists, and store the flag in the output parameter. */
   exists = access( tilendf, F_OK ) ? 0 : 1;
   parPut0l( "EXISTS", exists, status );

/* If the NDF does not exist, create it if required. */
   parGet0l( "CREATE", &create, status );
   if( !exists && create && *status == SAI__OK ) {

/* Write the NDF info to the screen. */
      msgSetc( "NDF",  tilendf );
      msgOutif( MSG__NORM, " ", "      NDF: ^NDF (created)", status );

/* Temporarily terminate the NDF path at the end of the subdirectory. */
      tilendf[ dirlen ] = 0;

/* Create the required directory (does nothing if the directory
   already exists).  It is given read/write/search permissions for owner
   and group, and read/search permissions for others. */
      (void) mkdir( tilendf, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH );

/* Replace the character temporarily overwritten above. */
      tilendf[ dirlen ] = '/';

/* Now create the tile's NDF. */
      ndfPlace( NULL, tilendf, &place, status );
      ndfNew( skytiling.type, 2, lbnd, ubnd, &place, &indf1, status );

/* Fill its data array with zeros. */
      ndfMap( indf1, "Data", skytiling.type, "WRITE/ZERO", &pntr, &el,
              status );

/* Store the WCS FrameSet. */
      ndfPtwcs( fs, indf1, status );

/* If the instrument jsatiles.have variance, fill the variance array with zeros. */
      if( skytiling.var ) {
         ndfMap( indf1, "Variance", skytiling.type, "WRITE/ZERO", &pntr,
                 &el, status );
      }

/* Create a SMURF extension. */
      ndfXnew( indf1, SMURF__EXTNAME, SMURF__EXTTYPE, 0, NULL, &xloc, status );

/* Store the tile number and instrument name in the extension. */
      datNew0I( xloc, "TILE", status );
      datFind( xloc, "TILE", &cloc, status );
      datPut0I( cloc, itile, status );
      datAnnul( &cloc, status );

      datNew0C( xloc, "INSTRUMENT", strlen( skytiling.name ), status );
      datFind( xloc, "INSTRUMENT", &cloc, status );
      datPut0C( cloc, skytiling.name, status );
      datAnnul( &cloc, status );

/* Create a weights NDF within the SMURF extension, and fill its data
   array with zeros. */
      ndfPlace( xloc, "WEIGHTS", &place, status );
      ndfNew( skytiling.type, 2, lbnd, ubnd, &place, &indf2, status );
      ndfMap( indf2, "Data", skytiling.type, "WRITE/ZERO", &pntr, &el,
              status );
      ndfPtwcs( fs, indf2, status );
      ndfAnnul( &indf2, status );

/* Annul the extension locator and the main NDF identifier. */
      datAnnul( &xloc, status );
      ndfAnnul( &indf1, status );

/* Write the NDF info to the screen. */
   } else {
      msgSetc( "NDF",  tilendf );
      msgSetc( "E",  exists ? "exists" : "does not exist" );
      msgOut( " ", "      NDF: ^NDF (^E)", status );
   }

/* Initialise TBND and TLBND to indicate no overlap. */
   tlbnd[ 0 ] = 1;
   tlbnd[ 1 ] = 1;
   tubnd[ 0 ] = 0;
   tubnd[ 1 ] = 0;

/* Attempt to to get an AST Region (assumed to be in some 2D sky coordinate
   system) using parameter "TARGET". */
   if( *status == SAI__OK ) {
      kpg1Gtobj( "TARGET", "Region",
                 (void (*)( void )) F77_EXTERNAL_NAME(ast_isaregion),
                 &obj, status );

/* Annul the error if none was obtained. */
      if( *status == PAR__NULL ) {
         errAnnul( status );

/* Otherwise, use the supplied object. */
      } else {
         target = (AstRegion *) obj;

/* If the target Region is 3-dimensional, remove the third axis, which
   is assumed to be a spectral axis. */
         if( astGetI( target, "Naxes" ) == 3 ) {
            axes[ 0 ] = 1;
            axes[ 1 ] = 2;
            target = astPickAxes( target, 2, axes, NULL );
         }

/* See if there is any overlap between the target and the tile. */
         overlap = NULL;
         flag = astOverlap( region, target );

         if( flag == 0 ) {
            msgOut( "", "      Cannot convert between the coordinate system of the "
                    "supplied target and the tile.", status );

         } else if( flag == 1 || flag == 6 ) {
            msgOut( "", "      There is no overlap between the target and the tile.",
                    status );

         } else if( flag == 2 ) {
            msgOut( "", "      The tile is contained within the target.",
                    status );
            tlbnd[ 0 ] = lbnd[ 0 ];
            tlbnd[ 1 ] = lbnd[ 1 ];
            tubnd[ 0 ] = ubnd[ 0 ];
            tubnd[ 1 ] = ubnd[ 1 ];

         } else if( flag == 3 ) {
            overlap = astCmpRegion( region, target, AST__AND, " " );

         } else if( flag == 4 ) {
            overlap = astCmpRegion( region, target, AST__AND, " " );

         } else if( flag == 5 ) {
            msgOut( "", "      The target and tile are identical.",
                    status );
            tlbnd[ 0 ] = lbnd[ 0 ];
            tlbnd[ 1 ] = lbnd[ 1 ];
            tubnd[ 0 ] = ubnd[ 0 ];
            tubnd[ 1 ] = ubnd[ 1 ];

         } else if( *status == SAI__OK ) {
            *status = SAI__OK;
            errRepf( "", "Unexpected value %d returned by astOverlap "
                     "(programming error).", status, flag );
         }

/* If a region containing the intersection of the tile and target was
   created above, map it into the grid coordinate system of the tile. */
         if( overlap ) {
            overlap = astMapRegion( overlap, astGetMapping( fs, AST__CURRENT,
                                                            AST__BASE ),
                                    astGetFrame( fs, AST__BASE ) );

/* Get its GRID bounds. */
            astGetRegionBounds( overlap, dlbnd, dubnd );

/* Convert to integer. */
            tlbnd[ 0 ] = ceil( dlbnd[ 0 ] - 0.5 );
            tlbnd[ 1 ] = ceil( dlbnd[ 1 ] - 0.5 );
            tubnd[ 0 ] = ceil( dubnd[ 0 ] - 0.5 );
            tubnd[ 1 ] = ceil( dubnd[ 1 ] - 0.5 );

/* Convert to PIXEL indices within the tile. */
            tlbnd[ 0 ] += lbnd[ 0 ] - 1;
            tlbnd[ 1 ] += lbnd[ 1 ] - 1;
            tubnd[ 0 ] += lbnd[ 0 ] - 1;
            tubnd[ 1 ] += lbnd[ 1 ] - 1;

            msgOutf( "", "      The target overlaps section (%d:%d,%d:%d).",
                     status, tlbnd[ 0 ], tubnd[ 0 ], tlbnd[ 1 ], tubnd[ 1 ] );
         }
      }
   }

/* Store the pixel index bounds of the tiles overlap with the target. */
   parPut1i( "TLBND", 2, tlbnd, status );
   parPut1i( "TUBND", 2, tubnd, status );

/* Arrive here if an error occurs. */
   L999:;

/* Free resources. */
   tilendf = astFree( tilendf );

/* End the AST context. */
   astEnd;

/* Issue a status indication.*/
   msgBlank( status );
   if( *status == SAI__OK ) {
      msgOutif( MSG__VERB, "", "JSATILEINFO succeeded.", status);
   } else {
      msgOutif( MSG__VERB, "", "JSATILEINFO failed.", status);
   }
}