Last modified: 13 August 2013

Name: H5Dset_extent

Signature:

herr_t H5Dset_extent( hid_t dset_id, const hsize_t size[] )

Purpose:

Changes the sizes of a dataset’s dimensions.

Description:

H5Dset_extent sets the current dimensions of the chunked dataset dset_id to the sizes specified in size.

size is a 1-dimensional array with n elements, where n is the rank of the dataset’s current dataspace.

This function can be applied to the following datasets:

A chunked dataset with unlimited dimensions
A chunked dataset with fixed dimensions if the new dimension sizes are less than the maximum sizes set with maxdims (see H5Screate_simple)
An external dataset with unlimited dimensions
An external dataset with fixed dimensions if the new dimension sizes are less than the maximum sizes set with maxdims
Note that external datasets are always contiguous and can be extended only along the first dimension.

Space on disk is immediately allocated for the new dataset extent if the dataset’s space allocation time is set to H5D_ALLOC_TIME_EARLY.

Fill values will be written to the dataset in either of the following situations, but not otherwise:

If the dataset’s fill time is set to H5D_FILL_TIME_IFSET and a fill value is defined (see H5Pset_fill_time and H5Pset_fill_value)
If the dataset’s fill time is set to H5D_FILL_TIME_ALLOC (see H5Pset_alloc_time)

Notes:

If the sizes specified in size are smaller than the dataset’s current dimension sizes, H5Dset_extent will reduce the dataset’s dimension sizes to the specified values. It is the user application’s responsibility to ensure that valuable data is not lost as H5Dset_extent does not check.

Except for external datasets, H5Dset_extent is for use with chunked datasets only, not contiguous datasets.

If a dataset is open for either writing or reading data when H5Dset_extent is called, the dataset’s dataspace must be refreshed before more data is written to the dataset and should be refreshed before any further data is read. This can be accomplished with a call to H5Dget_space.

Parameters:

hid_t `dset_id`	IN: Dataset identifier
const hsize_t `size[]`	IN: Array containing the new magnitude of each dimension of the dataset.

Returns:

Returns a non-negative value if successful; otherwise returns a negative value.

Fortran90 Interface: H5Dset_extent

SUBROUTINE h5dset_extent_f(dataset_id, size, hdferr)
  IMPLICIT NONE 
  INTEGER(HID_T), INTENT(IN) :: dataset_id   ! Dataset identifier
  INTEGER(HSIZE_T), DIMENSION(*), INTENT(IN) :: size 
                                             ! Array containing 
                                             ! dimensions’ sizes   
  INTEGER, INTENT(OUT) :: hdferr             ! Error code:
                                             ! 0 on success and -1 on failure
END SUBROUTINE h5dset_extent_f

See Also:

H5Pset_alloc_time
H5Pset_fill_time
H5Pset_fill_value H5Screate_simple
H5Dget_space

History:

Release	Change
1.6.0	Function implemented but not supported in this release.
1.8.0	Function supported in this release.