If you want to look at an interaction between continuous variables, then create a new continuous variable that is the product of the two and test whether that is 0 doug
On 05/12/2015 01:46 PM, Sarah Banducci wrote: > I'm trying to see if two behavioral variables interact (they are > factors 1 and 2) while controlling for the demographics also included > in the fsgd file. I would also like to run an interaction with age and > factor1. > > Here are the first few lines of my fsgd file. > Thanks > > GroupDescriptorFile 1 > Title STX > Class Male > Class Female > VariablesAge_demeanedEdu_demeanedFactor1Factor2 > InputF01_1Female-5.088888891.855555560.90.93 > InputF02_1Male1.91111111-0.144444440.850.85 > > On Fri, May 8, 2015 at 3:51 PM, Douglas N Greve > <gr...@nmr.mgh.harvard.edu <mailto:gr...@nmr.mgh.harvard.edu>> wrote: > > what are you trying to test an interaction between? Can you send the > first lines of your fsgd file? > > On 05/07/2015 10:41 AM, Sarah Banducci wrote: > > Hi all- > > I have been trying to determine the most appropriate way to set > up an > > interaction contrast for glmfit. For my purposes I'm interested in > > looking at the interaction two performance variables while covarying > > demographics. I have 2 classes set to male and female and the first > > columns in my fsgd file are demeaned age and education. > > > > I have found 3 ways people suggest setting up an interaction > contrast: > > 1- Putting the contrast in one row: > > 0 0 0 0 -.5 -.5 .5 .5 > > > > 2- Using two rows for the contrast: > > 0 0 0 0 .5 .5 0 0 > > 0 0 0 0 0 0 .5 .5 > > > > 3- Creating an actual interaction term where the values are > multiplied > > together in a new column of the fsgd file > > 0 0 0 0 0 0 0 0 .5 .5 > > > > I would be grateful to know how people set up this contrast. Also I > > would like to know how you run it (positive or negative) and > > subsequently how you interpret the results. > > > > > > Thanks, > > Sarah Banducci > > > > > > _______________________________________________ > > Freesurfer mailing list > > Freesurfer@nmr.mgh.harvard.edu > <mailto:Freesurfer@nmr.mgh.harvard.edu> > > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > -- > Douglas N. Greve, Ph.D. > MGH-NMR Center > gr...@nmr.mgh.harvard.edu <mailto:gr...@nmr.mgh.harvard.edu> > Phone Number: 617-724-2358 <tel:617-724-2358> > Fax: 617-726-7422 <tel:617-726-7422> > > Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting > <http://surfer.nmr.mgh.harvard.edu/fswiki/BugReporting> > FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 > www.nmr.mgh.harvard.edu/facility/filedrop/index.html > <http://www.nmr.mgh.harvard.edu/facility/filedrop/index.html> > Outgoing: > ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/ > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu <mailto:Freesurfer@nmr.mgh.harvard.edu> > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > > The information in this e-mail is intended only for the person to > whom it is > addressed. If you believe this e-mail was sent to you in error and > the e-mail > contains patient information, please contact the Partners > Compliance HelpLine at > http://www.partners.org/complianceline . If the e-mail was sent to > you in error > but does not contain patient information, please contact the > sender and properly > dispose of the e-mail. > > > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer -- Douglas N. Greve, Ph.D. MGH-NMR Center gr...@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422 Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 www.nmr.mgh.harvard.edu/facility/filedrop/index.html Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/ _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
