Problem with weight function

Main Forum
1

Hi,

I’m sending the anyscript file and the C3D as you asked me earlier. And my version is:

AnyBody version: 5.2.0.3070 Build 15484.49920

[i]"Hi,

I have a little problem, when i want to use a weight function to put to a marker. I first put in the AnyInputC3D class[/i][i]

ConstructWeightFunUsingResidualOnOff = On;[/i][i]

but then when put “play” it show an error like this:[/i][i]

ERROR(OBJ1) : C:/Doc…gs/a…6/D…p/p…o/D…S/Javi_dardos.any : C3D.Points.Markers.M008.Weight.Ts : The values in Ts must be monotonically increasing[/i][i]

The thing is that, I´m not using the Marker M008 yet.[/i][i]

What I have to do?[/i] "

Lincoln

2

Hi Lincoln,

There is a way for AnyInputC3D class to determine which markers will be used in the class.
You can use the ‘MarkerLabels’ option like this:
MarkerLabels = {“M000”, “M001”, “M002”, “M003”, “M004”, “M005”};

But then still the other markers will be moved to the ‘Main.MyArmModel.C3D.Points.ProcessedData’ folder.

So if you use ‘ConstructWeightFunUsingResidualOnOff = On’ option then still it seems that AnyBody will complain about M008 marker.

It seems that there is a very significant dropout in M008 marker.
It will take some time for us to figure out what the problem of your C3D file is.

But for your research, the easiest way is to remove M008 marker.

Best regards,
Moonki

3

Dear Lincoln,

I think the issue could be related to the default transition time assumed in the weight functions if your data has periods with very short dropouts. It is specified by the WeightTransitionTime variable in the c3d object. Default is 0.1 second. If you set it smaller than your sampling time, my guess is that the error will disappear. However, this also means that the marker will drop out very suddenly in the analysis, which likely will create significant discontinuities in the kinematic result.

So, I would suggest that you look through the data and gapfill all the very small gaps so that you can switch markers in and out over a period of time that is longer than just a few samples.

Best regards
Michael Skipper Andersen
Associate Professor
The AnyBody Research Group

4

Sorry, but how I gapfill all the very small gaps? it exist a class or something

5

http://wiki.anyscript.org/index.php/All_about_Kinematics#How_can_I_use_the_weight_function_ConstructWeightFunUsingResidualOnOff_in_a_model_when_markers_drop_out.3F

6

Dear Lincoln,

Gapfilling is usually an option in the software you used to collect the motion capture data. Have a look there.

Best regards
Michael Skipper Andersen
Associate Professor
The AnyBody Research Group