FUNCTION HDF_VD_VDATAINFO, HDFID, VDATANAME ;+ ; NAME: ; HDF_VD_VDATAINFO ; ; PURPOSE: ; Return information about a Vdata in a HDF file. ; ; CATEGORY: ; HDF utilities. ; ; CALLING SEQUENCE: ; RESULT = HDF_VD_VDATAINFO(HDFID, VDATANAME) ; ; INPUTS: ; HDFID Identifier of HDF file opened by caller with HDF_OPEN. ; VDATANAME Name of Vdata. ; ; OPTIONAL INPUTS: ; None. ; ; KEYWORD PARAMETERS: ; None. ; ; OUTPUTS: ; An anonymous structure containing information about the Vdata. ; The fields in the structure are as follows: ; NAME Name of the Vdata ('' if Vdata not found). ; NFIELDS Number of fields (-1 if Vdata not found). ; FIELDNAMES Array of field names ('' if Vdata not found). ; NRECORDS Number of records (-1 if Vdata not found). ; ; OPTIONAL OUTPUTS: ; None ; ; COMMON BLOCKS: ; None ; ; SIDE EFFECTS: ; None. ; ; RESTRICTIONS: ; Requires IDL 5.0 or higher (square bracket array syntax). ; ; EXAMPLE: ; ;file = 'sdsvdata.hdf' ;hdfid = hdf_open(file) ;result = hdf_vd_vdatainfo(hdfid, 'Vdata with mixed types') ;hdf_close, hdfid ;help, result, /structure ; ; MODIFICATION HISTORY: ; Liam.Gumley@ssec.wisc.edu ; http://cimss.ssec.wisc.edu/~gumley ; $Id: hdf_vd_vdatainfo.pro,v 1.2 2000/01/05 15:53:21 gumley Exp $ ; ; Copyright (C) 1999, 2000 Liam E. Gumley ; ; This program is free software; you can redistribute it and/or ; modify it under the terms of the GNU General Public License ; as published by the Free Software Foundation; either version 2 ; 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 General Public License for more details. ; ; You should have received a copy of the GNU General Public License ; along with this program; if not, write to the Free Software ; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. ;- rcs_id = '$Id: hdf_vd_vdatainfo.pro,v 1.2 2000/01/05 15:53:21 gumley Exp $' ;- Check arguments if (n_params() ne 2) then message, 'Usage: RESULT = HDF_SD_VDATAINFO(HDFID, VDATANAME)' if (n_elements(hdfid) eq 0) then message, 'Argument HDFID is undefined' if (n_elements(vdataname) eq 0) then message, 'Argument VDATANAME is undefined' ;- Set default return values name = '' nfields = -1 fieldnames = '' nrecords = -1 ;- Get the index for the vdata index = hdf_vd_find(hdfid, vdataname) ;- If the vdata is valid, get vdata information if (index gt 0) then begin ;- Attach to the vdata vdataid = hdf_vd_attach(hdfid, index) ;- Get information hdf_vd_get, vdataid, name=name, nfields=nfields, fields=fields, count=nrecords ;- Detach from the vdata hdf_vd_detach, vdataid ;- Convert field name string to array fieldnames = str_sep(fields, ',', /trim) endif ;- Return result to caller return, {name:name, nfields:nfields, fieldnames:fieldnames, nrecords:nrecords} END