I was hoping to use 3dfim+ to calculate the cross-correlation of a alpha power time series with the measured FMRI time series for each voxel. But an error occur:Input ideal time series file ‘EO_alpha_ps_conv_HRF_ts_normalized.txt’ is too short. I am sure my FMRI time series has 187 data points and my alpha time series also has 187 data points.

I am wondering if txt. is not fit to be a ideal_file fomat.

Are your time series in a row or column? If I recall 3dfim+ likes the ideal file in a column. To convert from row to column is trivial, just add a ’ at the end of your ideal file name on the 3dfim+ command line. Though you will more than likely need to add a \ before the ’ in order to prevent the shell from interpreting it.

You command will look something like:
3dfim+ -input input+tlrc.HEAD -ideal_file EO_alpha_ps_conv_HRF_ts_normalized.txt' -out Correlation -bucket correlation