Link to home
Start Free TrialLog in
Avatar of chudyksg
chudyksgFlag for United Kingdom of Great Britain and Northern Ireland

asked on

jtransforms problem

Can somebody help me with that. I am using an fft library jtransforms. When I apply the fft to an array:

 double[][] array = new double[][] {{1,1,1,1},{1,1,1,1}};
DoubleFFT_2D fft = new DoubleFFT_2D(2,2);
fft.realForwardFull(array);

Then I am getting the following results:
[4.0, 0.0, 0.0, -1.0]
[0.0, 0.0, 0.0, 0.0]

In the api http://incanter.org/docs/parallelcolt/api/edu/emory/mathcs/jtransforms/fft/DoubleFFT_2D.html#realForwardFull(double[][]) it says that "To get back the original data, use complexInverse on the output of this method."

so I am doing:
fft.complexInverse(array, false);
and I am getting:
[4.0, -1.0, 4.0, 1.0]
[4.0, -1.0, 4.0, 1.0]

where I want to get back to the original data which is only 1's.


Avatar of Mick Barry
Mick Barry
Flag of Australia image

Thats weird. Poor documentation though, makes it hard to work out whats going on
ASKER CERTIFIED SOLUTION
Avatar of Mick Barry
Mick Barry
Flag of Australia image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial