POSVELACC optimisation

Dear AnyBody,

I am trying to do a comparison of optimisation methods available in
GaitApplication2. When trying to run the model on POSVELACC in the studygait.txt
file I am getting the following ERROR;

failed to read desired sample in marker file; (first time step) ; dummy.txt

I’ve checked the dummy.txt file and it is the same for my POSONLY and SCALE
optimisations which both work.

Any thoughts on why POSVELACC is failing would be greatly appreciated.

many thanks

Peter

Hey Peter,

The answer is rather simple.

When you want to perform velocity and acceleration analysis as well, you need to
provide the time derivatives of the marker trajectories as input. If you look in
the reference manual for the GaitApplication2, you will see that in the MARKER
specification, after the filename with marker data, two additional filenames
should be provided, i.e. one with the velocity of the marker trajectories and
one with the acceleration of the marker trajectories.

Since we did not need these when performing position analysis and scaling
studies, we just put some dummy files (hence the name dummy.txt).

The format in these files should be the same as for the marker position data,
i.e. time x , y, z. The easiest way to obtain this data is to use the
interpostion functions in AnyBody, similarly to what was done for the marker
position data. Have a look in the MarkerMover.any file and construct two new
output file objects.

There is one thing that I should clarify, however. When you want to do velocity
and acceleration analysis, you need to specify a constant weight for the markers
(your weight.txt file) otherwise you will get incorrect results. It is simply an
interface feature that is missing (time-derivatives of the weight functions
cannot be provided yet), and noone has ever needed it so it has not had much
priority to implement it.

I hope that helps.

Best regards
Michael Skipper Andersen
The AnyBody Research Project.

To: anyscript@yahoogroups.com
From: peter.worsley@yahoo.co.uk
Date: Thu, 19 Mar 2009 10:54:27 +0000
Subject: [AnyScript] POSVELACC optimisation

         Dear AnyBody,

I am trying to do a comparison of optimisation methods available in
GaitApplication2. When trying to run the model on POSVELACC in the studygait.txt
file I am getting the following ERROR;

failed to read desired sample in marker file; (first time step) ; dummy.txt

I’ve checked the dummy.txt file and it is the same for my POSONLY and SCALE
optimisations which both work.

Any thoughts on why POSVELACC is failing would be greatly appreciated.

many thanks

Peter


Drag n’ drop—Get easy photo sharing with Windows Live™ Photos.

http://www.microsoft.com/windows/windowslive/products/photos.aspx

[Non-text portions of this message have been removed]

Hey Michael,

I have outputed the velocities and the accelerations files for each marker, but
I am unsure on how to feed them into the model. Do I need to construct one
dummy.txt file with both the velocities and accelerations, and if so what order
does the data need to be in?

many thanks

Peter

— On Thu, 19/3/09, Michael Skipper Andersen <msandersen60@hotmail.com> wrote:
From: Michael Skipper Andersen <msandersen60@hotmail.com>
Subject: RE: [AnyScript] POSVELACC optimisation
To: anyscript@yahoogroups.com
Date: Thursday, 19 March, 2009, 11:36 AM

Hey Peter,

The answer is rather simple.

When you want to perform velocity and acceleration analysis as well, you need
to provide the time derivatives of the marker trajectories as input. If you look
in the reference manual for the GaitApplication2, you will see that in the
MARKER specification, after the filename with marker data, two additional
filenames should be provided, i.e. one with the velocity of the marker
trajectories and one with the acceleration of the marker trajectories.

Since we did not need these when performing position analysis and scaling
studies, we just put some dummy files (hence the name dummy.txt).

The format in these files should be the same as for the marker position data,
i.e. time x , y, z. The easiest way to obtain this data is to use the
interpostion functions in AnyBody, similarly to what was done for the marker
position data. Have a look in the MarkerMover.any file and construct two new
output file objects.

There is one thing that I should clarify, however. When you want to do velocity
and acceleration analysis, you need to specify a constant weight for the markers
(your weight.txt file) otherwise you will get incorrect results. It is simply an
interface feature that is missing (time-derivatives of the weight functions
cannot be provided yet), and noone has ever needed it so it has not had much
priority to implement it.

I hope that helps.

Best regards
Michael Skipper Andersen
The AnyBody Research Project.

To: anyscript@yahoogroups.com
From: peter.worsley@yahoo.co.uk
Date: Thu, 19 Mar 2009 10:54:27 +0000
Subject: [AnyScript] POSVELACC optimisation

         Dear AnyBody,

I am trying to do a comparison of optimisation methods available in
GaitApplication2. When trying to run the model on POSVELACC in the studygait.txt
file I am getting the following ERROR;

failed to read desired sample in marker file; (first time step) ; dummy.txt

I’ve checked the dummy.txt file and it is the same for my POSONLY and SCALE
optimisations which both work.

Any thoughts on why POSVELACC is failing would be greatly appreciated.

many thanks

Peter


Drag n’ dropâ€"Get easy photo sharing with Windows Liveâ„¢ Photos.

http://www.microsoft.com/windows/windowslive/products/photos.aspx

[Non-text portions of this message have been removed]


Users of the AnyBody Modeling System help each other create biomechanical
models in the AnyScript language.Yahoo! Groups Links

[Non-text portions of this message have been removed]

Hey Peter,

If you want it to be setup automatically in the same way you have for the marker
position data, you need to make the change in the DataForConfigFile.any file. In
that file there is a list of marker specifications with the keyword MARKER.

In the line for each marker, the dummy.txt file is written two times in a row.
In all those lines, you should replace the first dummy.txt filename with the
filename of the velocity data file for that specific marker and the second with
the acceleration data for the marker.

I hope that answers your question.

Best regards
Michael Skipper Andersen
The AnyBody Research Project

To: anyscript@yahoogroups.com
From: peter.worsley@yahoo.co.uk
Date: Thu, 19 Mar 2009 12:12:14 +0000
Subject: RE: [AnyScript] POSVELACC optimisation

         Hey Michael,

I have outputed the velocities and the accelerations files for each marker, but
I am unsure on how to feed them into the model. Do I need to construct one
dummy.txt file with both the velocities and accelerations, and if so what order
does the data need to be in?

many thanks

Peter

— On Thu, 19/3/09, Michael Skipper Andersen <msandersen60@hotmail.com> wrote:

From: Michael Skipper Andersen <msandersen60@hotmail.com>

Subject: RE: [AnyScript] POSVELACC optimisation

To: anyscript@yahoogroups.com

Date: Thursday, 19 March, 2009, 11:36 AM

Hey Peter,

The answer is rather simple.

When you want to perform velocity and acceleration analysis as well, you need

to provide the time derivatives of the marker trajectories as input. If you look

in the reference manual for the GaitApplication2, you will see that in the

MARKER specification, after the filename with marker data, two additional

filenames should be provided, i.e. one with the velocity of the marker

trajectories and one with the acceleration of the marker trajectories.

Since we did not need these when performing position analysis and scaling

studies, we just put some dummy files (hence the name dummy.txt).

The format in these files should be the same as for the marker position data,

i.e. time x , y, z. The easiest way to obtain this data is to use the

interpostion functions in AnyBody, similarly to what was done for the marker

position data. Have a look in the MarkerMover.any file and construct two new

output file objects.

There is one thing that I should clarify, however. When you want to do velocity

and acceleration analysis, you need to specify a constant weight for the markers

(your weight.txt file) otherwise you will get incorrect results. It is simply an

interface feature that is missing (time-derivatives of the weight functions

cannot be provided yet), and noone has ever needed it so it has not had much

priority to implement it.

I hope that helps.

Best regards

Michael Skipper Andersen

The AnyBody Research Project.

To: anyscript@yahoogroups.com

From: peter.worsley@yahoo.co.uk

Date: Thu, 19 Mar 2009 10:54:27 +0000

Subject: [AnyScript] POSVELACC optimisation

Dear AnyBody,

I am trying to do a comparison of optimisation methods available in

GaitApplication2. When trying to run the model on POSVELACC in the studygait.txt

file I am getting the following ERROR;

failed to read desired sample in marker file; (first time step) ; dummy.txt

I’ve checked the dummy.txt file and it is the same for my POSONLY and SCALE

optimisations which both work.

Any thoughts on why POSVELACC is failing would be greatly appreciated.

many thanks

Peter


Drag n’ drop—Get easy photo sharing with Windows Live™ Photos.

http://www.microsoft.com/windows/windowslive/products/photos.aspx

[Non-text portions of this message have been removed]


Users of the AnyBody Modeling System help each other create biomechanical

models in the AnyScript language.Yahoo! Groups Links

[Non-text portions of this message have been removed]


News, entertainment and everything you care about at Live.com. Get it now!
http://www.live.com/getstarted.aspx

[Non-text portions of this message have been removed]

Hey Michael,

thankyou for your advice, everythings working fine now. I’m currently running a
monte-carlo variance study on markerpos and scaling inputs for the 2 types of
optimisation (SCALE, and POSVELACC) compared to unoptimised data. I will forward
you on the results once I have completed 1000 cycles.

best wishes

Peter

— On Thu, 19/3/09, Michael Skipper Andersen <msandersen60@hotmail.com> wrote:
From: Michael Skipper Andersen <msandersen60@hotmail.com>
Subject: RE: [AnyScript] POSVELACC optimisation
To: anyscript@yahoogroups.com
Date: Thursday, 19 March, 2009, 12:23 PM

Hey Peter,

If you want it to be setup automatically in the same way you have for the
marker position data, you need to make the change in the DataForConfigFile.any
file. In that file there is a list of marker specifications with the keyword
MARKER.

In the line for each marker, the dummy.txt file is written two times in a row.
In all those lines, you should replace the first dummy.txt filename with the
filename of the velocity data file for that specific marker and the second with
the acceleration data for the marker.

I hope that answers your question.

Best regards
Michael Skipper Andersen
The AnyBody Research Project

To: anyscript@yahoogroups.com
From: peter.worsley@yahoo.co.uk
Date: Thu, 19 Mar 2009 12:12:14 +0000
Subject: RE: [AnyScript] POSVELACC optimisation

         Hey Michael,

I have outputed the velocities and the accelerations files for each marker, but
I am unsure on how to feed them into the model. Do I need to construct one
dummy.txt file with both the velocities and accelerations, and if so what order
does the data need to be in?

many thanks

Peter

— On Thu, 19/3/09, Michael Skipper Andersen <msandersen60@hotmail.com>
wrote:

From: Michael Skipper Andersen <msandersen60@hotmail.com>

Subject: RE: [AnyScript] POSVELACC optimisation

To: anyscript@yahoogroups.com

Date: Thursday, 19 March, 2009, 11:36 AM

Hey Peter,

The answer is rather simple.

When you want to perform velocity and acceleration analysis as well, you need

to provide the time derivatives of the marker trajectories as input. If you
look

in the reference manual for the GaitApplication2, you will see that in the

MARKER specification, after the filename with marker data, two additional

filenames should be provided, i.e. one with the velocity of the marker

trajectories and one with the acceleration of the marker trajectories.

Since we did not need these when performing position analysis and scaling

studies, we just put some dummy files (hence the name dummy.txt).

The format in these files should be the same as for the marker position data,

i.e. time x , y, z. The easiest way to obtain this data is to use the

interpostion functions in AnyBody, similarly to what was done for the marker

position data. Have a look in the MarkerMover.any file and construct two new

output file objects.

There is one thing that I should clarify, however. When you want to do velocity

and acceleration analysis, you need to specify a constant weight for the
markers

(your weight.txt file) otherwise you will get incorrect results. It is simply
an

interface feature that is missing (time-derivatives of the weight functions

cannot be provided yet), and noone has ever needed it so it has not had much

priority to implement it.

I hope that helps.

Best regards

Michael Skipper Andersen

The AnyBody Research Project.

To: anyscript@yahoogroups.com

From: peter.worsley@yahoo.co.uk

Date: Thu, 19 Mar 2009 10:54:27 +0000

Subject: [AnyScript] POSVELACC optimisation

Dear AnyBody,

I am trying to do a comparison of optimisation methods available in

GaitApplication2. When trying to run the model on POSVELACC in the
studygait.txt

file I am getting the following ERROR;

failed to read desired sample in marker file; (first time step) ; dummy.txt

I’ve checked the dummy.txt file and it is the same for my POSONLY and SCALE

optimisations which both work.

Any thoughts on why POSVELACC is failing would be greatly appreciated.

many thanks

Peter


Drag n’ dropâ€"Get easy photo sharing with Windows Liveâ„¢ Photos.

http://www.microsoft.com/windows/windowslive/products/photos.aspx

[Non-text portions of this message have been removed]


Users of the AnyBody Modeling System help each other create biomechanical

models in the AnyScript language.Yahoo! Groups Links

[Non-text portions of this message have been removed]


News, entertainment and everything you care about at Live.com. Get it now!
http://www.live.com/getstarted.aspx

[Non-text portions of this message have been removed]


Users of the AnyBody Modeling System help each other create biomechanical
models in the AnyScript language.Yahoo! Groups Links

[Non-text portions of this message have been removed]