Developer Reference

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DFTI_NUMBER_OF_TRANSFORMS

If you need to perform a large number of identical FFTs, you can do this in a single call to a
DftiCompute*
function with the value of the
DFTI_NUMBER_OF_TRANSFORMS
configuration parameter equal to the actual number of the transforms. The default value of this parameter is one. You can set this parameter to a positive integer value using the
MKL_LONG
data type
. When setting the number of transforms to a value greater than one, you also need to specify the distance between the input data sets and the distance between the output data sets using one of the
DFTI_INPUT_DISTANCE
and
DFTI_OUTPUT_DISTANCE
configuration parameters or both.
  • The data sets to be transformed must not have common elements.
  • All the sets of data must be located within the same memory block.
To better understand the use of the
DFTI_NUMBER_OF_TRANSFORMS
configuration parameter, see this example in your
Intel® oneAPI Math Kernel Library
directory:
./examples/dftc/source/config_number_of_transforms.c

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.