In some situations, you may need to perform a number of FFTs of the same dimension and lengths. For example, you may need to transform a number of one-dimensional data sets of the same length. To specify this number, use the DFTI_NUMBER_OF_TRANSFORMS parameter, which has the default value of 1. You can set this parameter to a positive integer value using the Integer data type in Fortran and MKL_LONG data type in C.
Note
The data sets have no common elements. The distance parameter is required if the number of transforms is greater than one.