/* Copyright 2018 University Corporation for Atmospheric

   Research/Unidata. See COPYRIGHT file for more info. */

/**

   @file

   The functions in this file define, inquire about, and rename

   dimensions.

*/

#include "ncdispatch.h"

/**

   @defgroup dimensions Dimensions

   Dimensions are used to define the shape of data in netCDF.

   Dimensions for a netCDF dataset are defined when it is created,

   while the netCDF dataset is in define mode. Additional dimensions

   may be added later by reentering define mode. A netCDF dimension

   has a name and a length. In a netCDF classic or 64-bit offset file,

   at most one dimension can have the unlimited length, which means

   variables using this dimension can grow along this dimension. In a

   netCDF-4 file multiple unlimited dimensions are supported.

   There is a suggested limit (1024) to the number of dimensions that

   can be defined in a single netCDF dataset. The limit is the value

   of the predefined macro ::NC_MAX_DIMS. The purpose of the limit is

   to make writing generic applications simpler. They need only

   provide an array of ::NC_MAX_DIMS dimensions to handle any netCDF

   dataset. The implementation of the netCDF library does not enforce

   this advisory maximum, so it is possible to use more dimensions, if

   necessary, but netCDF utilities that assume the advisory maximums

   may not be able to handle the resulting netCDF datasets.

   ::NC_MAX_VAR_DIMS, which must not exceed ::NC_MAX_DIMS, is the

   maximum number of dimensions that can be used to specify the shape

   of a single variable. It is also intended to simplify writing

   generic applications.

   Ordinarily, the name and length of a dimension are fixed when the

   dimension is first defined. The name may be changed later, but the

   length of a dimension (other than the unlimited dimension) cannot

   be changed without copying all the data to a new netCDF dataset

   with a redefined dimension length.

   Dimension lengths in the C interface are type size_t rather than

   type int to make it possible to access all the data in a netCDF

   dataset on a platform that only supports a 16-bit int data type,

   for example MSDOS. If dimension lengths were type int instead, it

   would not be possible to access data from variables with a

   dimension length greater than a 16-bit int can accommodate.

   A netCDF dimension in an open netCDF dataset is referred to by a

   small integer called a dimension ID. In the C interface, dimension

   IDs are 0, 1, 2, ..., in the order in which the dimensions were

   defined.

   Operations supported on dimensions are:

   - Create a dimension, given its name and length.

   - Get a dimension ID from its name.

   - Get a dimension's name and length from its ID.

   - Rename a dimension.

*/

/** @{ */

/**

   Define a new dimension. The function nc_def_dim() adds a new

   dimension to an open netCDF dataset in define mode. It returns (as an

   argument) a dimension ID, given the netCDF ID, the dimension name, and

   the dimension length. At most one unlimited length dimension, called

   the record dimension, may be defined for each classic or 64-bit offset

   netCDF dataset. NetCDF-4 datasets may have multiple unlimited

   dimensions.

   @param ncid NetCDF or group ID, from a previous call to nc_open(),

   nc_create(), nc_def_grp(), or associated inquiry functions such as

   nc_inq_ncid().

   @param name Name of the dimension to be created.

   @param len Length of the dimension to be created. Use NC_UNLIMITED for

   unlimited dimensions.

   @param idp Pointer where dimension ID will be stored.

   @return ::NC_NOERR No error.

   @return ::NC_EBADID Not a valid ID.

   @return ::NC_EMAXNAME Name is too long.

   @return ::NC_EBADNAME Name breaks netCDF name rules.

   @return ::NC_EINVAL Invalid input.

   @return ::NC_ENOTINDEFINE Not in define mode.

   @return ::NC_EDIMSIZE Invalid dimension size.

   @return ::NC_EUNLIMIT NC_UNLIMITED size already in use

   @return ::NC_EMAXDIMS NC_MAX_DIMS exceeded [not enforced after 4.5.0]

   @return ::NC_ENAMEINUSE String match to name in use

   @return ::NC_ENOMEM Memory allocation (malloc) failure

   @return ::NC_EPERM Write to read only

   @section nc_def_dim_example Example

   Here is an example using nc_def_dim() to create a dimension named lat of

   length 18 and a unlimited dimension named rec in a new netCDF dataset

   named foo.nc:

   @code

   #include <netcdf.h>

   ...

   int status, ncid, latid, recid;

   ...

   status = nc_create("foo.nc", NC_NOCLOBBER, &ncid);

   if (status != NC_NOERR) handle_error(status);

   ...

   status = nc_def_dim(ncid, "lat", 18L, &latid);

   if (status != NC_NOERR) handle_error(status);

   status = nc_def_dim(ncid, "rec", NC_UNLIMITED, &recid);

   if (status != NC_NOERR) handle_error(status);

   @endcode

   @author Glenn Davis, Russ Rew, Ed Hartnett, Dennis Heimbigner, Ward

   Fisher

*/

int

nc_def_dim(int ncid, const char *name, size_t len, int *idp)

{

    NC* ncp;

    int stat = NC_check_id(ncid, &ncp);

    if(stat != NC_NOERR) return stat;

    TRACE(nc_def_dim);

    return ncp->dispatch->def_dim(ncid, name, len, idp);

}

/**

   Find the ID of a dimension from the name.

   The function nc_inq_dimid returns (as an argument) the ID of a

   netCDF dimension, given the name of the dimension. If ndims is the

   number of dimensions defined for a netCDF dataset, each dimension

   has an ID between 0 and ndims-1.

   @param ncid NetCDF or group ID, from a previous call to nc_open(),

   nc_create(), nc_def_grp(), or associated inquiry functions such as

   nc_inq_ncid().

   @param name Name of the dimension.

   @param idp Pointer where dimension ID will be stored.

   @return ::NC_NOERR No error.

   @return ::NC_EBADID Not a valid ID.

   @return ::NC_EBADDIM Invalid dimension ID.

   @author Glenn Davis, Russ Rew, Ed Hartnett, Dennis Heimbigner, Ward

   Fisher

*/

int

nc_inq_dimid(int ncid, const char *name, int *idp)

{

    NC* ncp;

    int stat = NC_check_id(ncid, &ncp);

    if(stat != NC_NOERR) return stat;

    TRACE(nc_inq_dimid);

    return ncp->dispatch->inq_dimid(ncid,name,idp);

}

/**

   Find the name and length of a dimension.

   The length for the unlimited dimension, if any, is the number of

   records written so far.

   @param ncid NetCDF or group ID, from a previous call to nc_open(),

   nc_create(), nc_def_grp(), or associated inquiry functions such as

   nc_inq_ncid().

   @param dimid Dimension ID, from a previous call to nc_inq_dimid() or

   nc_def_dim().

   @param name Returned dimension name. The caller must allocate space

   for the returned name. The maximum possible length, in characters, of

   a dimension name is given by the predefined constant

   ::NC_MAX_NAME. (This doesn't include the null terminator, so declare

   your array to be size NC_MAX_NAME+1). The returned character array

   will be null-terminated.

   @param lenp Pointer to location for returned length of dimension. For

   the unlimited dimension, this is the number of records written so far.

   @return ::NC_NOERR No error.

   @return ::NC_EBADID Not a valid ID.

   @return ::NC_EBADDIM Invalid dimension ID or name.

   @section nc_inq_dim_example Example

   Here is an example using nc_inq_dim() to determine the length of a

   dimension named lat, and the name and current maximum length of the

   unlimited dimension for an existing netCDF dataset named foo.nc:

   @code

   #include <netcdf.h>

   ...

   int status, ncid, latid, recid;

   size_t latlength, recs;

   char recname[NC_MAX_NAME+1];

   ...

   status = nc_open("foo.nc", NC_NOWRITE, &ncid);

   if (status != NC_NOERR) handle_error(status);

   status = nc_inq_unlimdim(ncid, &recid);

   if (status != NC_NOERR) handle_error(status);

   ...

   status = nc_inq_dimid(ncid, "lat", &latid);

   if (status != NC_NOERR) handle_error(status);

   status = nc_inq_dimlen(ncid, latid, &latlength);

   if (status != NC_NOERR) handle_error(status);

   status = nc_inq_dim(ncid, recid, recname, &recs);

   if (status != NC_NOERR) handle_error(status);

   @endcode

   @author Glenn Davis, Russ Rew, Ed Hartnett, Dennis Heimbigner, Ward

   Fisher

*/

int

nc_inq_dim(int ncid, int dimid, char *name, size_t *lenp)

{

    NC* ncp;

    int stat = NC_check_id(ncid, &ncp);

    if(stat != NC_NOERR) return stat;

    TRACE(nc_inq_dim);

    return ncp->dispatch->inq_dim(ncid,dimid,name,lenp);

}

/**

   Rename a dimension.

   This function renames an existing dimension in a netCDF dataset

   open for writing. You cannot rename a dimension to have the same

   name as another dimension.

   For netCDF classic and 64-bit offset files, if the new name is

   longer than the old name, which has been flushed to disk, the

   netCDF dataset must be in define mode.

   For netCDF-4 files the length of the name is not checked against

   the length of the old name, even for classic model files. This is

   due to the difficulty of exactly reproducing classic library

   behavior in this case.

   @param ncid NetCDF or group ID, from a previous call to nc_open(),

   nc_create(), nc_def_grp(), or associated inquiry functions such as

   nc_inq_ncid().

   @param dimid Dimension ID, from a previous call to nc_inq_dimid()

   or nc_def_dim().

   @param name New name for dimension. Must be a null-terminated

   string with length less than ::NC_MAX_NAME.

   @return ::NC_NOERR No error.

   @return ::NC_EBADID Not a valid ID.

   @return ::NC_EBADDIM Invalid dimension ID or name.

   @return ::NC_ENAMEINUSE String match to name in use

   @return ::NC_ENOMEM Memory allocation (malloc) failure

   @return ::NC_EPERM Write to read only

   @return ::NC_ENOTINDEFINE Not in define mode and new name is longer

   than old.

   @section nc_rename_dim_example Example

   Here is an example using nc_rename_dim to rename the dimension lat

   to latitude in an existing netCDF dataset named foo.nc:

   @code

   #include <netcdf.h>

   ...

   int status, ncid, latid;

   ...

   status = nc_open("foo.nc", NC_WRITE, &ncid);

   if (status != NC_NOERR) handle_error(status);

   ...

   status = nc_redef(ncid);

   if (status != NC_NOERR) handle_error(status);

   status = nc_inq_dimid(ncid, "lat", &latid);

   if (status != NC_NOERR) handle_error(status);

   status = nc_rename_dim(ncid, latid, "latitude");

   if (status != NC_NOERR) handle_error(status);

   status = nc_enddef(ncid);

   if (status != NC_NOERR) handle_error(status);

   @endcode

   @author Glenn Davis, Russ Rew, Ed Hartnett, Dennis Heimbigner, Ward

   Fisher

*/

int

nc_rename_dim(int ncid, int dimid, const char *name)

{

    NC* ncp;

    int stat = NC_check_id(ncid, &ncp);

    if(stat != NC_NOERR) return stat;

    TRACE(nc_rename_dim);

    return ncp->dispatch->rename_dim(ncid,dimid,name);

}

/**

   Find the number of dimensions.

   In a classic model netCDF file, this function returns the number of

   defined dimensions. In a netCDF-4/HDF5 file, this function returns

   the number of dimensions available in the group specified by ncid,

   which may be less than the total number of dimensions in a file. In

   a netCDF-4/HDF5 file, dimensions are in all sub-groups,

   sub-sub-groups, etc.

   @param ncid NetCDF or group ID, from a previous call to nc_open(),

   nc_create(), nc_def_grp(), or associated inquiry functions such as

   nc_inq_ncid().

   @param ndimsp Pointer where number of dimensions will be

   written. Ignored if NULL.

   @return ::NC_NOERR  No error.

   @return ::NC_EBADID Not a valid ID.

   @author Glenn Davis, Russ Rew, Ed Hartnett, Dennis Heimbigner, Ward

   Fisher

*/

int

nc_inq_ndims(int ncid, int *ndimsp)

{

    NC* ncp;

    int stat = NC_check_id(ncid, &ncp);

    if(stat != NC_NOERR) return stat;

    if(ndimsp == NULL) return NC_NOERR;

    TRACE(nc_inq_ndims);

    return ncp->dispatch->inq(ncid,ndimsp,NULL,NULL,NULL);

}

/**

   Find the ID of the unlimited dimension.

   This function finds the ID of the unlimited dimension. For

   netCDF-4/HDF5 files (which may have more than one unlimited

   dimension), the ID of the first unlimited dimesnion is

   returned. For these files, nc_inq_unlimdims() will return all the

   unlimited dimension IDs.

   @param ncid NetCDF or group ID, from a previous call to nc_open(),

   nc_create(), nc_def_grp(), or associated inquiry functions such as

   nc_inq_ncid().

   @param unlimdimidp Pointer where unlimited dimension ID will be

   stored. If there is no unlimited dimension, -1 will be stored

   here. Ignored if NULL.

   @return ::NC_NOERR  No error.

   @return ::NC_EBADID Not a valid ID.

   @author Glenn Davis, Russ Rew, Ed Hartnett, Dennis Heimbigner, Ward

   Fisher

*/

int

nc_inq_unlimdim(int ncid, int *unlimdimidp)

{

    NC* ncp;

    int stat = NC_check_id(ncid, &ncp);

    if(stat != NC_NOERR) return stat;

    TRACE(nc_inq_unlimdim);

    return ncp->dispatch->inq_unlimdim(ncid,unlimdimidp);

}

/**

   Find out the name of a dimension.

   @param ncid NetCDF or group ID, from a previous call to nc_open(),

   nc_create(), nc_def_grp(), or associated inquiry functions such as

   nc_inq_ncid().

   @param dimid Dimension ID, from a previous call to nc_inq_dimid()

   or nc_def_dim().

   @param name Returned dimension name. The caller must allocate space

   for the returned name. The maximum possible length, in characters,

   of a dimension name is given by the predefined constant

   ::NC_MAX_NAME. (This doesn't include the null terminator, so

   declare your array to be size NC_MAX_NAME+1). The returned

   character array will be null-terminated. Ignored if NULL.

   @return ::NC_NOERR   No error.

   @return ::NC_EBADID  Not a valid ID.

   @return ::NC_EBADDIM Invalid dimension ID or name.

   @section nc_inq_dim_example2 Example

   Here is an example using nc_inq_dim() to determine the length of a

   dimension named lat, and the name and current maximum length of the

   unlimited dimension for an existing netCDF dataset named foo.nc:

   @code

   #include <netcdf.h>

   ...

   int status, ncid, latid, recid;

   size_t latlength, recs;

   char recname[NC_MAX_NAME+1];

   ...

   status = nc_open("foo.nc", NC_NOWRITE, &ncid);

   if (status != NC_NOERR) handle_error(status);

   status = nc_inq_unlimdim(ncid, &recid);

   if (status != NC_NOERR) handle_error(status);

   ...

   status = nc_inq_dimid(ncid, "lat", &latid);

   if (status != NC_NOERR) handle_error(status);

   status = nc_inq_dimlen(ncid, latid, &latlength);

   if (status != NC_NOERR) handle_error(status);

   status = nc_inq_dim(ncid, recid, recname, &recs);

   if (status != NC_NOERR) handle_error(status);

   @endcode

   @author Glenn Davis, Russ Rew, Ed Hartnett, Dennis Heimbigner, Ward

   Fisher

*/

int

nc_inq_dimname(int ncid, int dimid, char *name)

{

    NC* ncp;

    int stat = NC_check_id(ncid, &ncp);

    if(stat != NC_NOERR) return stat;

    if(name == NULL) return NC_NOERR;

    TRACE(nc_inq_dimname);

    return ncp->dispatch->inq_dim(ncid,dimid,name,NULL);

}

/**

   Find the length of a dimension.

   The length for the unlimited dimension, if any, is the number of

   records written so far.

   @param ncid NetCDF or group ID, from a previous call to nc_open(),

   nc_create(), nc_def_grp(), or associated inquiry functions such as

   nc_inq_ncid().

   @param dimid Dimension ID, from a previous call to nc_inq_dimid()

   or nc_def_dim().

   @param lenp Pointer where the length will be stored.

   @return ::NC_NOERR   No error.

   @return ::NC_EBADID  Not a valid ID.

   @return ::NC_EBADDIM Invalid dimension ID or name.

   @section nc_inq_dim_example3 Example

   Here is an example using nc_inq_dim() to determine the length of a

   dimension named lat, and the name and current maximum length of the

   unlimited dimension for an existing netCDF dataset named foo.nc:

   @code

   #include <netcdf.h>

   ...

   int status, ncid, latid, recid;

   size_t latlength, recs;

   char recname[NC_MAX_NAME+1];

   ...

   status = nc_open("foo.nc", NC_NOWRITE, &ncid);

   if (status != NC_NOERR) handle_error(status);

   status = nc_inq_unlimdim(ncid, &recid);

   if (status != NC_NOERR) handle_error(status);

   ...

   status = nc_inq_dimid(ncid, "lat", &latid);

   if (status != NC_NOERR) handle_error(status);

   status = nc_inq_dimlen(ncid, latid, &latlength);

   if (status != NC_NOERR) handle_error(status);

   status = nc_inq_dim(ncid, recid, recname, &recs);

   if (status != NC_NOERR) handle_error(status);

   @endcode

   @author Glenn Davis, Russ Rew, Ed Hartnett, Dennis Heimbigner, Ward

   Fisher

*/

int

nc_inq_dimlen(int ncid, int dimid, size_t *lenp)

{

    NC* ncp;

    int stat = NC_check_id(ncid, &ncp);

    if(stat != NC_NOERR) return stat;

    if(lenp == NULL) return NC_NOERR;

    TRACE(nc_inq_dimlen);

    return ncp->dispatch->inq_dim(ncid,dimid,NULL,lenp);

}

/** @} */