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Initial split of Guide from rest of documentation. Using 'tagfiles' to cross-reference from one documentation set to the other works, but then it drags all of the 'external' related pages into the index of the other. Modified visability of the external groups and pages. Adding proper section names to 'Example' sections, to avoid Doxygen warnings. Initial split of Guide from rest of documentation. Using 'tagfiles' to cross-reference from one documentation set to the other works, but then it drags all of the 'external' related pages into the index of the other. Modified visability of the external groups and pages. Adding proper section names to 'Example' sections, to avoid Doxygen warnings. Reorganizing documentation into two separate doxygen projects. Moved .texi documents into an old directory. Pulled the tutorial document into a separate document, similar to the guide document. Turned on treeview
209 lines
6.1 KiB
C
209 lines
6.1 KiB
C
/** \file
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Attribute inquiry functions
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These functions find out about attributes.
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Copyright 2011 University Corporation for Atmospheric
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Research/Unidata. See \ref copyright file for more info. */
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#include "ncdispatch.h"
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/** \name Learning about Attributes
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Functions to learn about the attributes in a file. */
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/*! \{ */ /* All these functions are part of this named group... */
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/**
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\ingroup attributes
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Return information about a netCDF attribute.
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The function nc_inq_att returns the attribute's type and length.
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\param ncid NetCDF or group ID, from a previous call to nc_open(),
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nc_create(), nc_def_grp(), or associated inquiry functions such as
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nc_inq_ncid().
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\param varid Variable ID of the attribute's variable, or ::NC_GLOBAL
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for a global attribute.
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\param name Pointer to the location for the returned attribute \ref
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object_name. \ref ignored_if_null.
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\param xtypep Pointer to location for returned attribute \ref
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data_type. \ref ignored_if_null.
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\param lenp Pointer to location for returned number of values
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currently stored in the attribute. For attributes of type ::NC_CHAR,
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you should not assume that this includes a trailing zero byte; it
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doesn't if the attribute was stored without a trailing zero byte, for
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example from a FORTRAN program. Before using the value as a C string,
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make sure it is null-terminated. \ref ignored_if_null.
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\section nc_inq_att_example Example
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Here is an example using nc_inq_att() to find out the type and length of
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a variable attribute named valid_range for a netCDF variable named rh
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and a global attribute named title in an existing netCDF dataset named
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foo.nc:
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\code
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#include <netcdf.h>
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...
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int status;
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int ncid;
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int rh_id;
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nc_type vr_type, t_type;
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size_t vr_len, t_len;
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...
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status = nc_open("foo.nc", NC_NOWRITE, &ncid);
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if (status != NC_NOERR) handle_error(status);
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...
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status = nc_inq_varid (ncid, "rh", &rh_id);
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if (status != NC_NOERR) handle_error(status);
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...
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status = nc_inq_att (ncid, rh_id, "valid_range", &vr_type, &vr_len);
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if (status != NC_NOERR) handle_error(status);
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status = nc_inq_att (ncid, NC_GLOBAL, "title", &t_type, &t_len);
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if (status != NC_NOERR) handle_error(status);
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\endcode
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*/
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int
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nc_inq_att(int ncid, int varid, const char *name, nc_type *xtypep,
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size_t *lenp)
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{
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NC* ncp;
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int stat = NC_check_id(ncid, &ncp);
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if(stat != NC_NOERR) return stat;
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return ncp->dispatch->inq_att(ncid, varid, name, xtypep, lenp);
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}
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/**
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\ingroup attributes
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Find an attribute ID.
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\param ncid NetCDF or group ID, from a previous call to nc_open(),
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nc_create(), nc_def_grp(), or associated inquiry functions such as
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nc_inq_ncid().
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\param varid Variable ID of the attribute's variable, or ::NC_GLOBAL for
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a global attribute.
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\param name Attribute \ref object_name.
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\param idp Pointer to location for returned attribute number that
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specifies which attribute this is for this variable (or which global
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attribute). If you already know the attribute name, knowing its number
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is not very useful, because accessing information about an attribute
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requires its name.
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*/
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int
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nc_inq_attid(int ncid, int varid, const char *name, int *idp)
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{
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NC* ncp;
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int stat = NC_check_id(ncid, &ncp);
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if(stat != NC_NOERR) return stat;
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return ncp->dispatch->inq_attid(ncid, varid, name, idp);
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}
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/**
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\ingroup attributes
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Find the name of an attribute.
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\param ncid NetCDF or group ID, from a previous call to nc_open(),
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nc_create(), nc_def_grp(), or associated inquiry functions such as
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nc_inq_ncid().
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\param varid Variable ID of the attribute's variable, or ::NC_GLOBAL
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for a global attribute.
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\param attnum Attribute number. The attributes for each variable are
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numbered from 0 (the first attribute) to natts-1, where natts is the
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number of attributes for the variable, as returned from a call to
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nc_inq_varnatts().
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\param name Pointer to the location for the returned attribute \ref
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object_name.
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*/
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int
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nc_inq_attname(int ncid, int varid, int attnum, char *name)
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{
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NC* ncp;
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int stat = NC_check_id(ncid, &ncp);
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if(stat != NC_NOERR) return stat;
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return ncp->dispatch->inq_attname(ncid, varid, attnum, name);
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}
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/**
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\ingroup attributes
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Find number of global or group attributes.
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\param ncid NetCDF or group ID, from a previous call to nc_open(),
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nc_create(), nc_def_grp(), or associated inquiry functions such as
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nc_inq_ncid().
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\param nattsp Pointer where number of global or group attributes will be
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written. \ref ignored_if_null.
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*/
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int
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nc_inq_natts(int ncid, int *nattsp)
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{
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NC* ncp;
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int stat = NC_check_id(ncid, &ncp);
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if(stat != NC_NOERR) return stat;
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if(nattsp == NULL) return NC_NOERR;
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return ncp->dispatch->inq(ncid, NULL, NULL, nattsp, NULL);
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}
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/**
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\ingroup attributes
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Find the type of an attribute.
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\param ncid NetCDF or group ID, from a previous call to nc_open(),
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nc_create(), nc_def_grp(), or associated inquiry functions such as
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nc_inq_ncid().
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\param varid Variable ID of the attribute's variable, or ::NC_GLOBAL
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for a global or group attribute.
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\param name Attribute \ref object_name.
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\param xtypep Pointer to location for returned attribute \ref data_type.
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*/
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int
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nc_inq_atttype(int ncid, int varid, const char *name, nc_type *xtypep)
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{
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NC* ncp;
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int stat = NC_check_id(ncid, &ncp);
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if(stat != NC_NOERR) return stat;
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return ncp->dispatch->inq_att(ncid, varid, name, xtypep, NULL);
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}
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/**
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\ingroup attributes
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Find the length of an attribute.
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\param ncid NetCDF or group ID, from a previous call to nc_open(),
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nc_create(), nc_def_grp(), or associated inquiry functions such as
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nc_inq_ncid().
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\param varid Variable ID of the attribute's variable, or ::NC_GLOBAL
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for a global or group attribute.
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\param name Attribute \ref object_name.
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\param lenp Pointer to location for returned number of values
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currently stored in the attribute. Before using the value as a C
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string, make sure it is null-terminated. \ref ignored_if_null.
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*/
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int
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nc_inq_attlen(int ncid, int varid, const char *name, size_t *lenp)
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{
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NC* ncp;
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int stat = NC_check_id(ncid, &ncp);
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if(stat != NC_NOERR) return stat;
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return ncp->dispatch->inq_att(ncid, varid, name, NULL, lenp);
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}
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/*! \} */ /* End of named group ...*/
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