Error using CSD model on data

[cbinhb]

A bit new to using DiPy with fibertracking but keep getting this error when trying to use the CSD model on my data. Any clues as to what might be wrong?

/ifshome/cboyle/anaconda3/lib/python3.6/site-packages/dipy/reconst/csdeconv.py:130: UserWarning: Number of parameters required for the fit are more than the actual data points
warnings.warn(msg, UserWarning)

[arokem]

How many directions of measurements do you have in your data? What are you using as `sh_order` (the default value is 8). This warning typically arises when you are trying to fit the model with the `sh_order` set too high relative to the number of measurements in your data. For example, I believe using the default value requires at least 45 directions of measurements.

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On Thu, Jan 25, 2018 at 3:02 PM, cbinhb ***@***.***> wrote: A bit new to using DiPy with fibertracking but keep getting this error when trying to use the CSD model on my data. Any clues as to what might be wrong? /ifshome/cboyle/anaconda3/lib/python3.6/site-packages/dipy/reconst/csdeconv.py:130: UserWarning: Number of parameters required for the fit are more than the actual data points warnings.warn(msg, UserWarning) — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#1405>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAHPNh0OtgkyP-tEXTjbpWf9mDeNgi9oks5tOQf7gaJpZM4Rtn4V> .

[cbinhb]

Actually I think it was causing a problem when I used this line first (from the Dipy examples for CSD to calibrate response/ratio etc) and in turn used "response" in my csd_fit line.

response, ratio = auto_response(gtab, data, roi_radius=10, fa_thr=0.7)

It's indicating the "parameters" or arguments for the function are too many correct? So took "response" out of my CSD equation. Does this make sense?

You did give me some information I need with regard to sh_order since I wasn't sure what that was. How do you specify the default since I do have 45 (HARDI) directions?

[cbinhb]

it does give me error saying sh_order must be an even number when I try 45. Maybe it's 46?

[cbinhb]

The documentation is a bit confusing.

[cbinhb]

oops maybe you were right - getting the error again. My data has 46 directions, what should my csd_model equation have as parameters?

[cbinhb]

ok! reduced sh_order to 4 and it worked. I obviously need to figure out what SH number should be but for now I'm good. Thank you!

[arokem]

I would use 4 or 6. Given you have 46 directions, 8 is too much. I'll close this for now, but feel free to reopen if you run into more related issues.

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On Thu, Jan 25, 2018 at 4:02 PM, cbinhb ***@***.***> wrote: ok! reduced sh_order to 4 and it worked. I obviously need to figure out what SH number should be but for now I'm good. Thank you! — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#1405 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAHPNiH5pKGTTZ32NzQAFBGYyknUgb80ks5tORYFgaJpZM4Rtn4V> .

[cbinhb]

Thank you! On Thu, Jan 25, 2018 at 4:27 PM, Ariel Rokem <notifications@github.com> wrote:

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I would use 4 or 6. Given you have 46 directions, 8 is too much. I'll close this for now, but feel free to reopen if you run into more related issues. On Thu, Jan 25, 2018 at 4:02 PM, cbinhb ***@***.***> wrote: > ok! reduced sh_order to 4 and it worked. I obviously need to figure out > what SH number should be but for now I'm good. Thank you! > > — > You are receiving this because you commented. > Reply to this email directly, view it on GitHub > <#1405 (comment)>, or mute > the thread > <https://github.com/notifications/unsubscribe-auth/ AAHPNiH5pKGTTZ32NzQAFBGYyknUgb80ks5tORYFgaJpZM4Rtn4V> > . > — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#1405 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/Ahfddu1mTHLVG9Ajr5DNPO2t4X0keE1Aks5tORv2gaJpZM4Rtn4V> .