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Hi - this is now the "-e" option - see the randomise manual for more information on this. For most simple designs you don't need this - we'd need to know more about your model to be sure though. Cheers, Steve. On 28 Mar 2009, at 15:17, Agnieszka Burzynska wrote: > > Dear all > I found this post below in the archives and wonder whether I need to > use the –g flag for a desing similar to the one below. I dont find > the -g option in the current version of randomise and therefore I am > not sure what to do. > > My second question is: how much it matters to specify a group in the > first “group” column in the Glm-GUI? Is it just for user’s own > information? If I left all inputs with “1” but I specify groups in > the Evs( for EV only one subgroup has non-zero values, etc) , does > this first column still matter? > > Thank you, > Aga > > > >>> On 5 Mar 2008, at 16:55, : > >>> > >>>> > Hi Steve, > >>>> > > >>>> > Firstly I am not very familiar with the mathematics of design > matrix > >>>> > and contrast matrix. I am trying to get myself familiarized > with it, > >>>> > so kindly excuse me if any of my questions sound silly. > >>>> > > >>>> > I have two groups > >>>> > > >>>> > No of Controls: 13 > >>>> > No of Patients: 12 > >>>> > Behavioral data: Type1 (for both patients and controls) > >>>> > Behavioral data: Type 2 (for both patients and controls) > >>>> > > >>>> > I would like to set up the randomise option in TBSS to do > >>>> > correlation between the FA values and a behavioral measure > (Actually > >>>> > both - separately). There are two types of tests that I would > like > >>>> > to carry out. > >>>> > > >>>> > 1. Test whether the FA of all the subjects in both the > groups > >>>> > correlate with a behavioral measure. > >>>> > 2. Contrast the behavioral correlation between the two > groups. > >>>> > > >>>> > From some of the previous posts I initially assumed that I > needed > >>>> > two design matrices and one contrast matrix for both the > tests. But > >>>> > in the latest version of randomise that I downloaded it said > that > >>>> > confound regressors can be given in the main design matrix > itself. > >>>> > So I am assuming that we need only one design matrix and one > >>>> > contrast matrix for both of the above tests that I had > mentioned > >>>> > above. > >>>> > > >>>> > If the above assumptions I have made are right then I will > move on > >>>> > with the design and contrast matrices that I have for both of > the > >>>> > above tests. > >>>> > > >>>> > Test 2 - Contrast the behavioral correlation between the two > groups. > >>>> > > >>>> > So in this design matrix I had 2 groups and 4 EVs. In the > groups > >>>> > column I gave the value for first 13 subjects as 1 and for > the rest > >>>> > of the 12 subjects to be 2. The matrix given below is the > design > >>>> > matrix that I used for this testing. (b1-b25 is the behavioral > >>>> > values for each of the 25 subjects.) > >>>> > > >>>> > EV1 EV2 EV3 EV4 > >>>> > b1 0 1 0 > >>>> > b2 0 1 0 > >>>> > b3 0 1 0 > >>>> > b4 0 1 0 > >>>> > b5 0 1 0 > >>>> > b6 0 1 0 > >>>> > b7 0 1 0 > >>>> > b8 0 1 0 > >>>> > b9 0 1 0 > >>>> > b10 0 1 0 > >>>> > b11 0 1 0 > >>>> > b12 0 1 0 > >>>> > b13 0 1 0 > >>>> > 0 b14 0 1 > >>>> > 0 b15 0 1 > >>>> > 0 b16 0 1 > >>>> > 0 b17 0 1 > >>>> > 0 b18 0 1 > >>>> > 0 b19 0 1 > >>>> > 0 b20 0 1 > >>>> > 0 b21 0 1 > >>>> > 0 b22 0 1 > >>>> > 0 b23 0 1 > >>>> > 0 b24 0 1 > >>>> > 0 b25 0 1 > >>>> > > >>>> > From some of the past archives I found that the matrix that > contains > >>>> > the behavioral measures is the main matrix(used with -d) and > the > >>>> > matrix with the group membership information should be taken > as the > >>>> > confound matrix (used with -x). > >>> > >>> No, the group membership, which controls the exchangeability > blocks, > >>> should be passed in using the -g flag. There is no longer any > need for > >>> 'confound' matrices. > --------------------------------------------------------------------------- Stephen M. Smith, Professor of Biomedical Engineering Associate Director, Oxford University FMRIB Centre FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK +44 (0) 1865 222726 (fax 222717) [log in to unmask] http://www.fmrib.ox.ac.uk/~steve ---------------------------------------------------------------------------