Functions > Transforms and Filters > Example: dft and idft of a Matrix
Example: dft and idft of a Matrix
Use the dft and idft functions for finding the forward or inverse Discrete Fourier Transform of a matrix.
1. Define the dimensions of a data matrix.
2. Use the exp function to create a complex data matrix of dimensions MxN.
3. Use the dft function to calculate the Discrete Fourier Transform of A.
4. Use the definition of dft to calculate a specific element of Z.
5. Use the above definition to find a specific frequency element and compare it with the output of the dft function.
Gaussian idft
The idft function is the inverse transformation of dft. It accepts a real or complex matrix as its argument and returns a matrix of the same dimensions.
1. Show that the inverse transformation of a dft function is the function itself.
2. Use the previously defined matrix A, then show that the inverse transformation of a dft function is the function itself.
 Iz idft dft A A
3. Use the definition of idft to calculate any element of A.
4. Use the above definition to find a specific frequency element and compare it with the corresponding element in the output of the idft function.