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Hi Elif, i am not an expert, so i am not completely sure about this. But i think there is no problem, as you dont get an error, but only a warning. Every DCM matrix contains not specified connections, which can not be estimated. During estimation these connections get the value Nan, which is indicated by the displayed warning. So i think your estimation was finished correctly. The reason that you get this warning after the first step is, that iteration stops, if the changes from one step to the next are smaller than a threshold (1e-6 i think). This condition is met in your analysis after the first step (dp: 1.139079e-21). This is a little astonishing for me, but perhaps could be due to a very simple model? If i am wrong here one of the spm/dcm should please correct me. Hope this helps, Christian On Thu, 30 Jun 2005 01:26:49 +0100, Elif Ozdemir <[log in to unmask] HARVARD.EDU> wrote: >Dear all, > >I am conducting a DCM analysis on a dataset that we acquired from a subject >using a sparse temporal sampling method (TR=15, TA=1.75 sc). I have defined >three VOIs for two (out of four) conditions. When I do the estimation, I >get the error message below after the first iteration. I have read the >previous posts about this error and have the latest DCM updates. > >After getting the error message, I am still able review the results. The >histogram is drawn only for B probabilities, not for B modulatory effects. >In addition, even though the VOIs are circled, there are no numbers. > >I have replicated the results of the attention data from Dr.Penny's website >without these error messages. > >Any ideas how to fix this? Any input/help is greatly appreciated! >Thanks! > >Elif > >"E-Step(-): 1 F: -1.043264e+03 dp: 1.139079e-21 >Warning: Returning NaN for out of range arguments >> In /usr/local/spm2/spm_Ncdf.m at line 76 > In /usr/local/spm2/spm_dcm_estimate.m at line 72 > In /usr/local/spm2/spm_dcm_ui.m at line 312"