blackrey10
New member
- Joined
- Apr 21, 2020
- Messages
- 1
Hi! 
First of all, sorry for my english. I am not native. I hope you can understand me.
I have been working and trying to understand the Discrete Fourier Transform (DFT) and I think I did, but I have one doubt.
1) --> If we look the DFT like a multiplication of a vector by a Matrix, we have:
[Result vector v] = [matrix A (NxN)] x [Data vector d (with N componentes)]
--> I understand the data vector d like a sampled function in time. Each component n represent a point of the function.
--> I understand the matrix A like a base change matrix
--> I understand the result vector v like the data vector d changed base
2) Then I have a doubt:
from the mathematical point of view, the matrix A is square. But, ¿It must be square?
from the physical point of view, I want to check more frequencies (more components of the result vector) with the same data vector (Still N components). ¿Could I use a non square matrix?¿Could I use a matrix with more rows without change the number of columns?
I hope you can understand me. Thankss!!
First of all, sorry for my english. I am not native. I hope you can understand me.
I have been working and trying to understand the Discrete Fourier Transform (DFT) and I think I did, but I have one doubt.
1) --> If we look the DFT like a multiplication of a vector by a Matrix, we have:
[Result vector v] = [matrix A (NxN)] x [Data vector d (with N componentes)]
--> I understand the data vector d like a sampled function in time. Each component n represent a point of the function.
--> I understand the matrix A like a base change matrix
--> I understand the result vector v like the data vector d changed base
2) Then I have a doubt:
from the mathematical point of view, the matrix A is square. But, ¿It must be square?
from the physical point of view, I want to check more frequencies (more components of the result vector) with the same data vector (Still N components). ¿Could I use a non square matrix?¿Could I use a matrix with more rows without change the number of columns?
I hope you can understand me. Thankss!!