DWI -fslgrad arguments errors

1

Hello,
I am trying to learn how to analyze DWI images.
I have tried on my own data, but I had a bug with fslgrad on the bias correction function, which I will not detail, because I have solved it modifying some typo errors.
Then I have tried to train on data from andy’s brain blog videos, and followed his tuto.

At the first video, to convert format to mrtrix compatible format, when I use -fslgrad, I have the same bug that I used to have before :

mrconvert sub-CON02_ses-preop_acq-AP_dwi.mif -fslgrad sub-CON02_ses-preop_acq-AP_dwi.bvec sub-CON02_ses-preop_acq-AP_dwi.bval

I get error :

mrconvert: [ERROR] Expected exactly 2 arguments (1 supplied)
mrconvert: [ERROR] Usage: mrconvert input output
mrconvert: [ERROR] Yours: mrconvert sub-CON02_ses-preop_acq-AP_dwi.mif

So I have tried to swap the arguments and tried:

mrconvert -fslgrad sub-CON02_ses-preop_acq-AP_dwi.bvec sub-CON02_ses-preop_acq-AP_dwi.bval sub-CON02_ses-preop_acq-AP_dwi.mif

But still errors:

mrconvert: [ERROR] Expected exactly 2 arguments (1 supplied)
mrconvert: [ERROR] Usage: mrconvert input output
mrconvert: [ERROR] Yours: mrconvert sub-CON02_ses-preop_acq-AP_dwi.mif

What am I doing wrong? It’s basically the same scripts as in his videos, and still it does not work…
I just re-installed mrtrix3 yesterday, so basically I have the latest version I guess?

Thanks for you help,
Best
Fabien

2

mrconvert requires 2 arguments: 1 input file name (the file you are converting from) and 1 output file name (the file you are converting to).

In your examples you are only specifying 1 argument, hence the error [ERROR] Expected exactly 2 arguments (1 supplied).

To better understand how mrconvert works, consult its help page by running

mrconvert

(without any arguments). This works for all MRtrix commands.

1 Like
3

Hello,

Thanks for your time and your answer!

There was indeed an additional file in the tuto, i misread… Really sorry for that!

Best
Fabien