Implement a function that calculates 1D Discrete Cosine Transform (DCT-II) for each row of a given input matrix so that the outputs are in columns.
For example:
Input:
[1 0 0 0]
Gives:
mydct([1 0 0 0])
ans =
0.5
0.65328
0.5
0.2706
Solution Stats
Problem Comments
1 Comment
Solution Comments
Show comments
Loading...
Problem Recent Solvers22
Suggested Problems
-
4518 Solvers
-
Replace NaNs with the number that appears to its left in the row.
3071 Solvers
-
given 3 sides, find area of this triangle
823 Solvers
-
Construct an index vector from two input vectors in vectorized fashion
461 Solvers
-
Permute diagonal and antidiagonal
517 Solvers
More from this Author4
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
A fair warning to the challenger: the requested DCT-II is the orthogonal version, which means it needs to be multiplied by sqrt(2/N) where N is the size of the row, and the first element of the DCT x0 needs to be multiplied by 1/sqrt(2). It took me a while to understand. Wikipedia's formula is almost right, but it is missing those terms, which are mentioned only further below. Look at MATLAB's documentation (DCT-2), https://www.mathworks.com/help/signal/ref/dct.html, to find the proper formula.