Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 3/22/2024
Public
Document Table of Contents

DFTI_DIMENSION, DFTI_LENGTHS

The dimension of the transform is a positive integer value represented in an integer scalar of Integer data type. For a one-dimensional transform, the transform length is specified by a positive integer value represented in an integer scalar of Integer data type. For multi-dimensional (≥ 2) transform, the lengths of each of the dimensions are supplied in an integer array (of Integer data type).

DFTI_DIMENSION and DFTI_LENGTHS do not have a default value. To set them, use the DftiCreateDescriptor function and not the DftiSetValue function.

To better understand usage of the DFTI_DIMENSION and DFTI_LENGTHS configuration parameters, you can refer to basic examples of one-, two-, and three-dimensional transforms in your Intel® oneAPI Math Kernel Library (oneMKL) directory. Naming conventions for the examples are self-explanatory. For example, refer to these examples of single-precision two-dimensional transforms:

./examples/dftf/source/basic_sp_real_dft_2d.f90

./examples/dftf/source/basic_sp_complex_dft_2d.f90