idct {tidynorm} | R Documentation |
Inverse Discrete Cosine Transform
Description
The Inverse DCT
Usage
idct(y, n)
## S3 method for class 'numeric'
idct(y, n = length(y))
## S3 method for class 'matrix'
idct(y, n = nrow(y))
Arguments
y |
A vector or matrix of DCT coefficients |
n |
The desired length of the idct |
Details
Applies the Inverse DCT (see dct for more details).
x_j = \sqrt{2}y_0 + 2\sum_{k=1}^{N-1} y_k \cos\left(\frac{\pi k(2j+1)}{2J}\right)
Value
The returned value depends on the values in y
.
When passed a numeric vector, returns numeric vector of length n
.
When passed a matrix, returns a matrix with n
rows and the same number of columns as y
.
Examples
x <- seq(0, 1, length = 10)
y <- 5 + x + (2 * (x^2)) + (-2 * (x^4))
dct_coefs <- dct(y)
recovered_y <- idct(dct_coefs)
plot(y, recovered_y)
[Package tidynorm version 0.3.0 Index]