Hello.I have question relating to setting up a flexible factorial model with 2 groups, each group has 4 conditions.I have 3 factors: 1 = subject (independent, variance equal), 2 = group (independent, variance not equal), 3 = condition (not independent, variance equal)For the subject level, I entered in 20 subjects, for each subject, I entered in the the 4 scans: con_image 1,2,3,4. For conditions, I entered 1 2 3 4. Once all 20 subjects were completed, I entered 3 main effects, and interaction: main effect: 1, main effect: 2, main effect: 3, interaction: 2 3.The model did not run and I got the following error message:Running job #2
-----------------------------------------------------------------------
Running 'Factorial design specification'
Failed 'Factorial design specification'
Index exceeds matrix dimensions.
In file "C:\Documents and Settings\JWest\Desktop\spm8\config\spm_run_factorial_design.m" (v3067), function "spm_run_factorial_design" at line 482.The following modules did not run:
Failed: Factorial design specificationI feel like the error is in the subject level: either the scan or the conditions. I do not feel like the conditions step is correct. Can anyone please explain what I did wrong setting up my model.Thank you for any suggestions.JefJeffrey West, M.A.
Research Analyst
Maryland Psychiatric Research Center
Baltimore, Maryland 21228-0247
Phone: 410-402-6018
email: [log in to unmask]
Hi Jeff,You should enter conditions for subjects in a nscans x factor matrix. The rows are your scans (4 in your case) and the columns indicate the factors (2, one for group and one for condition, subject is automatically modelled).So for a subject in group 2 with scans for all four conditions you would need:[2 1
2 2
2 32 4]Make sure your scans are entered in the right order!Also, main effect for subjects doesn't need to be specified, this is done automatically (this is because you chose 'Subjects' at the 'Specify Subjects or all Scans & Factors').Good luck,PieterOn Mon, Feb 28, 2011 at 3:14 PM, Jeffrey West <[log in to unmask]> wrote:
Hello.I have question relating to setting up a flexible factorial model with 2 groups, each group has 4 conditions.I have 3 factors: 1 = subject (independent, variance equal), 2 = group (independent, variance not equal), 3 = condition (not independent, variance equal)For the subject level, I entered in 20 subjects, for each subject, I entered in the the 4 scans: con_image 1,2,3,4. For conditions, I entered 1 2 3 4. Once all 20 subjects were completed, I entered 3 main effects, and interaction: main effect: 1, main effect: 2, main effect: 3, interaction: 2 3.The model did not run and I got the following error message:Running job #2
-----------------------------------------------------------------------
Running 'Factorial design specification'
Failed 'Factorial design specification'
Index exceeds matrix dimensions.
In file "C:\Documents and Settings\JWest\Desktop\spm8\config\spm_run_factorial_design.m" (v3067), function "spm_run_factorial_design" at line 482.The following modules did not run:
Failed: Factorial design specificationI feel like the error is in the subject level: either the scan or the conditions. I do not feel like the conditions step is correct. Can anyone please explain what I did wrong setting up my model.Thank you for any suggestions.JefJeffrey West, M.A.
Research Analyst
Maryland Psychiatric Research Center
Baltimore, Maryland 21228-0247
Phone: 410-402-6018
email: [log in to unmask]