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Isis 3 Programmer Reference
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Isis 3 Programmer Reference
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Fourier Transform class. More...
#include <FourierTransform.h>
Public Member Functions | |
| FourierTransform () | |
| Constructs the FourierTransform object. | |
| ~FourierTransform () | |
| Destroys the FourierTransform object. | |
| std::vector< std::complex< double > > | Transform (std::vector< std::complex< double > > input) |
| Applies the Fourier transform on the input data and returns the result. | |
| std::vector< std::complex< double > > | Inverse (std::vector< std::complex< double > > input) |
| Applies the inverse Fourier transform on the input data and returns the result. | |
| bool | IsPowerOfTwo (int n) |
| Checks to see if the input integer is a power of two. | |
| int | lg (int n) |
| This function returns the floor of log2(n) | |
| int | BitReverse (int n, int x) |
| Reverses the binary representation of the input integer in the number of bits specified. | |
| int | NextPowerOfTwo (int n) |
| This function returns the next power of two greater than or equal to n. | |
Fourier Transform class.
This class is used to apply a Fourier transform to a vector of complex
data as well as the inverse Fourier transform. Applying the Fourier transform on data in the spatial domain will convert it to data in the Fourier (or frequency) domain. The inverse transform takes data from the frequency domain to the spatial.
If you would like to see FourierTransform being used in implementation, see fft.cpp or ifft.cpp.
Definition at line 33 of file FourierTransform.h.
| Isis::FourierTransform::FourierTransform | ( | ) |
Constructs the FourierTransform object.
Definition at line 14 of file FourierTransform.cpp.
| Isis::FourierTransform::~FourierTransform | ( | ) |
Destroys the FourierTransform object.
Definition at line 17 of file FourierTransform.cpp.
| int Isis::FourierTransform::BitReverse | ( | int | n, |
| int | x ) |
Reverses the binary representation of the input integer in the number of bits specified.
bitReverse(n,x) = n/2*(2^-a1 + 2^-a2 + ... + 2^-ak) where x = 2^a1 + 2^a2 + ... + 2^ak
| n | The number of bits |
| x | The input integer |
Definition at line 137 of file FourierTransform.cpp.
Referenced by Transform().
| std::vector< std::complex< double > > Isis::FourierTransform::Inverse | ( | std::vector< std::complex< double > > | input | ) |
Applies the inverse Fourier transform on the input data and returns the result.
| input | The data to be transformed. |
Definition at line 75 of file FourierTransform.cpp.
References Transform().
| bool Isis::FourierTransform::IsPowerOfTwo | ( | int | n | ) |
Checks to see if the input integer is a power of two.
| n | The input integer |
Definition at line 100 of file FourierTransform.cpp.
Referenced by NextPowerOfTwo().
| int Isis::FourierTransform::lg | ( | int | n | ) |
This function returns the floor of log2(n)
| n | The input integer |
Definition at line 116 of file FourierTransform.cpp.
Referenced by NextPowerOfTwo().
| int Isis::FourierTransform::NextPowerOfTwo | ( | int | n | ) |
This function returns the next power of two greater than or equal to n.
If n is a power of two, it returns n.
| n | The number of bits |
Definition at line 160 of file FourierTransform.cpp.
References IsPowerOfTwo(), and lg().
Referenced by Isis::ForstnerOperator::Interest(), and Transform().
| std::vector< std::complex< double > > Isis::FourierTransform::Transform | ( | std::vector< std::complex< double > > | input | ) |
Applies the Fourier transform on the input data and returns the result.
| input | The data to be transformed. |
Definition at line 28 of file FourierTransform.cpp.
References BitReverse(), NextPowerOfTwo(), and Isis::PI.
Referenced by Inverse().