Thank you for making these data available!

I might be missing something, but it looks like some of the b vectors are missing components. For example, the file: pp01_dwi_run01_A/bvecs, contains 136 elements in the first and second line, but only 135 elements in the last line. It's also not entirely clear to me how the 136 elements correspond to the 34 volumes in (for example) pp01_dwi_run01_A/pp01_dwi_run01_A.nii.gz. Similarly, there are 136 b values in pp01_dwi_run01_A/bvals. How do these correspond to the volumes in the nifti file? 

Thanks for clarifying! 

Ariel Rokem
http://arokem.org

Hi Ariel, 
Thank you for spotting this mistake. You are correct that a single value is missing for the third bvec row. The 136 elements should correspond to the combined 4 runs of 34 volumes but we agree that this is a bit confusing. We'll change the bvals and bvecs files to correspond to a single run. 

Note that since this data is acquired from a phillips scanner, the first volume corresponds to the B0 file, the next 32 volumes to the 32 directions, and finally the 34th volume is the weighted average of the 32 directions (also sometimes called an isotropic-weighted scan). This last volume has a bval of 1000 and x=0,y=0,z=0 for the bvecs. It is recommended that you remove this extra volume when you start to analyse the DWI data. 

Once I've update the files I'll send you an email.

Best regards,
Max