fails to open sample c3d trial (via Python wrapper)

[jjnurminen]

Hi,

I have used the btk Python wrapper successfully in the past.
Now I downloaded some sample c3d data from:
https://www.c3d.org/data/sample03.zip

I extracted the trials and tried the following code:

import btk
c3dfile = "gait-pig.c3d"
reader = btk.btkAcquisitionFileReader()
reader.SetFilename(c3dfile)
reader.Update()

However this causes the Python interpreter to crash. I get the following print at the console:

[BTK WARNING] gait-pig.c3d - The number of blocks to be read in the parameter section is different than the number of blocks read. The value kept is the number of blocks read.
[BTK ERROR] Impossible to set a scaling factor to 0.
[BTK ERROR] Impossible to set a scaling factor to 0.
[BTK ERROR] Impossible to set a scaling factor to 0.
[BTK ERROR] Impossible to set a scaling factor to 0.
[BTK ERROR] Impossible to set a scaling factor to 0.
[BTK ERROR] Impossible to set a scaling factor to 0.

I'd also note that the file opens just fine in Mokka, which uses btk. So maybe the problem is with the Python wrapper?

[kaufManu]

I have the same problem, were you able to find a solution?

[aaa34169]

I also get this error message with this c3d. notice you can get all markers though. I don t know how was built this c3d. i remember we found out an error related to the "subject" prefix if you work with multiple subjects. It s not my pratice. i would be happy to test a c3d construct from Nexus 2.6. notice i test with openMA and no warning come up. cheers

…

On 9 November 2017 at 14:03, kaufManu ***@***.***> wrote: I have the same problem, were you able to find a solution? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#13 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AC9GBbpTbgjJFON1IRFwSkSsT3H1B_Y8ks5s0wYMgaJpZM4HdDwv> .

-- ---------------------------------------------------------------------------------------------- Fabien Leboeuf Research fellow ( University of salford) ------------------------------------------------------------------------------------------------ - phD Mechanics-Biomechanics (university of Poitiers, FRANCE) ------------------------------------------------------------------------------------------------ College of Health & Social Care University of Salford Allerton Building Frederick Road Campus Salford, M6 6PU, UNITED KINGDOM ------------------------------------------------------------------------------------------------

[kaufManu]

@aaa34169 How can you get the markers? I tried to do this with the Python wrapper, but could not find the function. I could only make this work with the Matlab wrapper.

[aaa34169]

yes !

just with
acq.GetPoint("A22:RKNE").GetValues()

[kaufManu]

@aaa34169 this is what is throwing the error mentioned in the original post in my code. The Matlab function markers = btkGetMarkers(acq); also throws that error, but it still gives an output that I can use. However I could not find the equivalent of that function in the python wrapper.

[jjnurminen]

It crashes already when you do call Update(). See first postof thread.

I was never able to load that particular file, but Vicon Nexus produced files have worked OK so far.

[aaa34169]

when you wrote "crash".do You mean your python shell crashed ?

…

On 9 November 2017 at 15:18, Jussi Nurminen ***@***.***> wrote: It crashes already when you do call Update(). See first postof thread. I was never able to load that particular file, but Vicon Nexus produced files have worked OK so far. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#13 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AC9GBQ46hHXlIv5rTP81yv7_3IzAhodfks5s0xfIgaJpZM4HdDwv> .

-- ---------------------------------------------------------------------------------------------- Fabien Leboeuf Research fellow ( University of salford) ------------------------------------------------------------------------------------------------ - phD Mechanics-Biomechanics (university of Poitiers, FRANCE) ------------------------------------------------------------------------------------------------ College of Health & Social Care University of Salford Allerton Building Frederick Road Campus Salford, M6 6PU, UNITED KINGDOM ------------------------------------------------------------------------------------------------

[jjnurminen]

Yep, the Python interpreter throws a segmentation fault.