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Converts data from one specified datatype to another


H5T_CONVERT(src_type_id, dest_type_id, nelmts, buf, background, plist_id)


herr_t H5Tconvert( hid_t src_type_id, hid_t dest_type_id, size_t nelmts, void *buf, void *background, hid_t plist_id )


SUBROUTINE h5tconvert_f(src_id, dst_id, nelmts, buf, hdferr, background, plist_id)
    INTEGER(HID_T) , INTENT(IN)               :: src_id
    INTEGER(HID_T) , INTENT(IN)               :: dst_id
    INTEGER(SIZE_T), INTENT(IN)               :: nelmts
    TYPE(C_PTR)    , INTENT(INOUT)            :: buf
    INTEGER        , INTENT(OUT)              :: hdferr
    TYPE(C_PTR)    , INTENT(INOUT), OPTIONAL  :: background
    INTEGER(HID_T) , INTENT(IN)   , OPTIONAL  :: plist_id

hid_t src_type_idIN: Identifier for the source datatype
hid_t dest_type_idIN: Identifier for the destination datatype
size_t nelmtsIN: Size of array buf
void *bufIN/OUT: Array containing pre- and post-conversion values 
H5Tconvert will not resize this buffer; it must be large enough to hold the larger of the input and output data.
void *background    IN: Optional background buffer
hid_t plist_idIN: Dataset transfer property list identifier


 H5T_CONVERT converts nelmts elements from a source datatype, specified by src_type_id, to a destination datatype, dest_type_id. The source elements are packed in buf and on return the destination elements will be packed in buf. That is, the conversion is performed in place.

The optional background buffer is for use with compound datatypes. It is an array of nelmts values for the destination datatype which can then be merged with the converted values to recreate the compound datatype. For instance, background might be an array of structs with the a and b fields already initialized and the conversion of buf supplies the c and d field values.

The parameter plist_id contains the dataset transfer property list identifier which is passed to the conversion functions. As of Release 1.2, this parameter is only used to pass along the variable-length datatype custom allocation information.

Programming Note for C++ Developers Using C Functions:

If a C routine that takes a function pointer as an argument is called from within C++ code, the C routine should be returned from normally.

Examples of this kind of routine include callbacks such as H5P_SET_ELINK_CB  and H5P_SET_TYPE_CONV_CB and functions such as H5T_CONVERT and H5E_WALK2.

Exiting the routine in its normal fashion allows the HDF5 C library to clean up its work properly. In other words, if the C++ application jumps out of the routine back to the C++ “catch” statement, the library is not given the opportunity to close any temporary data structures that were set up when the routine was called. The C++ application should save some state as the routine is started so that any problem that occurs might be diagnosed.


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


Coming Soon!

Release    Change
1.8.8Fortran subroutine added.
1.6.3In C function, nelmts parameter type changed to size_t.
1.4.0In C function, nelmts parameter type changed to hsize_t.

--- Last Modified: May 10, 2019 | 02:26 PM