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mkl/examples/f/dft directory contains examples of using Discrete Fourier
Transform Interface (DFTI) for Fortran to compute various FFT problems.

Each example is a self-contained Fortran program.

Examples with prefix 'basic_' demonstrate simple ways to compute complex and
real Fast Fourier transforms. The programs may be used as quick start
templates. Files containing '_dp_'/'_sp_' in their names use double and single
precision, respectively.

Examples with prefix 'config_' demonstrate usage of DFTI configuration
parameters.

For every FFT computed in the example an initialization and verification
function is provided. Initialization function shows how the input data is
indexed and what input will produce a unit peak in the result. Verification
function checks if the unit peak is produced by the computation.

Every example uses dynamically allocated arrays for the data.  Sizes of the
transforms and parameters for verification are selected randomly.

Note: In some examples that show in-place real-to-complex and complex-to-real
transforms the different type arrays are storage associated by use of Cray
pointers, which is not a standard Fortran feature.

Refer to "Fast Fourier Transforms" chapter in Intel(R) oneMKL Reference Manual for detailed
description of the functions used in these examples.

Your feedback on the examples is welcome at Intel(R) oneMKL Forum site:
https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/bd-p/oneapi-math-kernel-library

