Dear Liam,

In my hands the best approach is to use expression i1*-1. After you can open your initial and the new image as overlays in MRIcron and treat their thresholds independently.

If you want to create a common mask for all suprathreshold values (positive and "negatvie") use Draw>Overlay comparisons>Union.

Hope this helps!

Vladimir

--- On Sun, 8/5/12, Liam Mason <[log in to unmask]> wrote:

From: Liam Mason <[log in to unmask]>
Subject: [SPM] Re-code zeros using ImCalc
To: [log in to unmask]
Date: Sunday, August 5, 2012, 3:40 PM

Hi list,

I have a map with value range -10 to +10 and I have masked out all non-significant voxels by setting them to zero. I want to view that map in MRIcron. This works fine if I ask for only positive values (e.g scale 1 - 10) but if I set the scale to include negative values all of the non-signficant (zero) values are shown.

I don't think MRIcron has a setting to not show zeros (e.g. set scale +1 to +10 AND -1 to -10) so I thought I could re-code the zero values to something really large (e.g. 999) and then set my scale to exclude these high values.

Something like:
    i1(==0) = 999
But this syntax isn't supported.

Any ideas?

Many thanks in advance!
Liam

---
School of Psychological Sciences
University of Manchester
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