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Unwrap

Unwrap modulus, waveName [, waveName ]...

The Unwrap operation scans through each named wave trying to undo the effect of a modulus operation.

Parameters

modulus is the value applied to the named waves through the mod function as if the command:

waveName = mod(waveName,modulus)

had been executed. It is this calculation which Unwrap attempts to undo.

Details

The Unwrap operation works with 1D waves only. See ImageUnwrapPhase for phase unwrapping in two dimensions..

Examples

If you perform an FFT on a wave, the result is a complex wave in rectangular coordinates. You can create a real wave which contains the phase of the result of the FFT with the command:

wave2 = imag(r2polar(wave1))

However the rectangular to polar conversion leaves the phase information modulo 2π. You can restore the phase information with the command:

Unwrap 2*pi, wave2

Because the first point of a wave that has been FFTed has no phase information, in this example you would precede the Unwrap command with the command:

wave2[0] = wave2[1]

See Also

mod, ImageUnwrapPhase