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--- jvs:fscan:manual:chapter2:expression:fft [2011/09/17 20:32]
voyvodic created
+++ jvs:fscan:manual:chapter2:expression:fft [2023/02/23 18:43] (current)
@@ Line 1: / Line 1: @@
 **fScan Reference Manual, Chapter 2 (CmdLineOptions:Expr): fft**
-===== fft -- =====
+===== fft -- Perform a fast Fourier transform =====
- **usage:  -expr fft**\\
+ **usage:  -expr fft flag [outwdsiz]**
+The FFT expression performs a fast Fourier transform (FFT) on an entire data set.
+The FLAG argument controls options as:
+FLAG:\\
+  * 1 - frequency space to image space (default: image to frequency)1-dimensional FFT
+  * 2 - 2-dimensional FFT (default: 1-dimensional FFT)
+  * 4 - input has phase (default: magnitude only, set phase to 0)
+  * 8 - output is complex (default: single value, magnitude only)
+  * 16 - output is phase only
+  * 32 - output is real only
+  * 48 - output is imaginary only
+  * 64 - magnitude and phase are highest dimension (default: lowest dimension)
+OUTWDSIZ is the output word size. The default is float32 if FLAG indicates single values ((FLAG&56)!=8), or cpx_float32 if (FLAG&56)==8.
 **See Also:**\\
 [[jvs:fscan|fScan Home]],

Brain Imaging & Analysis Center