Thanks for both replies.
Then I found the "ifft2" from Matlab gives different result from "fft( ,
inverse=T)" from R.
An example:
in R:
> temp <- matrix(c(1,4,2, 20), nrow=2)
> fft(temp)
[,1] [,2]
[1,] 27+0i -17+0i
[2,] -21+0i 15+0i
> fft(temp,inverse=T)
[,1] [,2]
[1,] 27+0i -17+0i
[2,] -21+0i 15+0i
In Matlab:
> A = [1,2;4,20];
> fft2(A)
Ans =
27 -17
-21 15
>ifft2(A)
Ans=
6.7500 -4.2500
-5.2500 3.7500
I also tried mvfft with inverse but can't get same result with "ifft2". Does
any function work?
Thanks,
Li
On 5/2/07, Sundar Dorai-Raj < [EMAIL PROTECTED]> wrote:
>
>
> I don't know Matlab or any of its functions, but the following produces
> the same output.
>
> z <- matrix(c(1, 4, 2, 20), nrow = 2)
> Re(fft(z))
>
> And from ?fft:
>
> When 'z' contains an array, 'fft' computes and returns the multivariate
> (spatial) transform.
>
> HTH,
>
> --sundar
>
[[alternative HTML version deleted]]
______________________________________________
[EMAIL PROTECTED] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
