I checked the masks dataset, and they seem to be already integral, so "-nscale" was of no help.

Thanks to your input I tried different flags with 3dcalc, and I succeded using "-datum short":

3dcalc -a clustCorr+orig -expr "a*100" -datum short -prefix clustCorr100

gives the desired output.

Davide

Here is the 3dinfo output for the clustCorr+orig mask dataset:

Dataset File: clustCorr+orig
Identifier Code: XYZ_8xpz0RUwd0I5BopcgNAt9A Creation Date: Fri Oct 7 12:34:35 2005
Dataset Type: Func-Bucket (-fbuc)
Byte Order: LSB_FIRST [this CPU native = LSB_FIRST]
Storage Mode: BRIK file
Data Axes Orientation:
first (x) = Anterior-to-Posterior
second (y) = Superior-to-Inferior
third (z) = Left-to-Right [-orient ASL]
R-to-L extent: -8.625 [R] -to- 8.625 [L] -step- 5.750 mm [ 4 voxels]
A-to-P extent: -119.062 [A] -to- 119.062 [P] -step- 1.875 mm [128 voxels]
I-to-S extent: -119.062 -to- 119.062 [S] -step- 1.875 mm [128 voxels]
Number of values stored at each pixel = 1
-- At sub-brick #0 '#8' datum type is byte: 0 to 9