Thank you so much. I applied the data to a 4D nii image (19 cases of 3D binary images) .
command line: randomise -i g2groups.nii.gz -o randomise_output_g2groups -d design_2groups.mat -t design_2groups.con -T -x -V -n 100 --debug
Design.mat
/NumWaves 2
/NumPoints 19
/PPheights 1.000000e+00 1.000000e+00
/Matrix
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
Design.con
/ContrastName1 group A > group B
/NumWaves 2
/NumContrasts 1
/PPheights 1.000000e+00
/RequiredEffect 3.228
/Matrix
1.000000e+00 -1.000000e+00
I did not specify a mask image. Could you please send me some information regarding how I should specify the mask image? Thank you so much.
Best,
Tiffany
----- Original Message -----
From: "Himanshu Joshi" <[log in to unmask]>
To: [log in to unmask]
Sent: Wednesday, June 19, 2013 9:26:48 PM
Subject: Re: [FSL] randomise
Hello Liu,
Can you further expand on
What data you are applying fslmaths randomise?
What is your commandline to ask for permutations (randomise commandline) ?
What is your Design.mat, Design.con file?
What is your mask for running those permutations?
Does your mask file and your input file shares the same properties ? Check in fslview and write back
After all these we would be able to solve your problem.
On Thu, Jun 20, 2013 at 9:26 AM, Ting Liu < [log in to unmask] > wrote:
Hi all,
I used FSLmaths randomise to compare differences between two groups.
I got the following warning at the 53th permutation. I guess my design matrix should be correct? I have 4 samples in one group, and 15 samples in the other group. Could it be that the size of the first group is too small? Could you please let me know what I might have missed? Thank you so much.
Warning: tfce has detected a large number of integral steps. This operation may require a great deal of time to complete.
....
Starting permutation 50
statistic Maximum: 2.31699
Starting permutation 51
statistic Maximum: 6.34533
Starting permutation 52
statistic Maximum: 2.02243
Starting permutation 53
statistic Maximum: 9.24119e+15
Warning: tfce has detected a large number of integral steps. This operation may require a great deal of time to complete.
--
Himanshu Joshi
M.Tech. Cognitive & Neuroscience.
Senior Research Fellow
Ph.D Scholar,
Department of Psychiatry
NIMHANS, Bangalore
http://mbial.weebly.com/himanshu-joshi.html
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