78 lines
2.8 KiB
C++
78 lines
2.8 KiB
C++
// Copyright (C) 2013 Davis E. King (davis@dlib.net)
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// License: Boost Software License See LICENSE.txt for the full license.
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#undef DLIB_FFt_ABSTRACT_Hh_
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#ifdef DLIB_FFt_ABSTRACT_Hh_
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#include "matrix_abstract.h"
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#include "../algs.h"
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namespace dlib
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{
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// ----------------------------------------------------------------------------------------
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bool is_power_of_two (
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const unsigned long& value
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);
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/*!
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ensures
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- returns true if value contains a power of two and false otherwise. As a
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special case, we also consider 0 to be a power of two.
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!*/
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// ----------------------------------------------------------------------------------------
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template <typename EXP>
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typename EXP::matrix_type fft (
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const matrix_exp<EXP>& data
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);
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/*!
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requires
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- data contains elements of type std::complex<>
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- is_vector(data) == true
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- is_power_of_two(data.size()) == true
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ensures
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- Computes the discrete Fourier transform of the given data vector and
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returns it. In particular, we return a matrix D such that:
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- D.nr() == data.nr()
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- D.nc() == data.nc()
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- D(0) == the DC term of the Fourier transform.
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- starting with D(0), D contains progressively higher frequency components
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of the input data.
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- ifft(D) == D
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- if DLIB_USE_FFTW is #defined then this function will use the very fast fftw
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library when given double precision matrices instead of dlib's default fft
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implementation. Note that you must also link to the fftw3 library to use
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this feature.
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!*/
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// ----------------------------------------------------------------------------------------
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template <typename EXP>
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typename EXP::matrix_type ifft (
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const matrix_exp<EXP>& data
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);
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/*!
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requires
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- data contains elements of type std::complex<>
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- is_vector(data) == true
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- is_power_of_two(data.size()) == true
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ensures
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- Computes the inverse discrete Fourier transform of the given data vector and
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returns it. In particular, we return a matrix D such that:
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- D.nr() == data.nr()
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- D.nc() == data.nc()
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- fft(D) == data
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- if DLIB_USE_FFTW is #defined then this function will use the very fast fftw
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library when given double precision matrices instead of dlib's default fft
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implementation. Note that you must also link to the fftw3 library to use
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this feature.
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!*/
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// ----------------------------------------------------------------------------------------
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}
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#endif // DLIB_FFt_ABSTRACT_Hh_
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