linear, non matrix P300

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OKI
Posts: 18
Joined: 23 Jul 2010, 05:53

linear, non matrix P300

Post by OKI » 12 Jul 2011, 04:22

Hello,

for a special P300 application, i need a non matrix interface for the P300 speller.

i tried to change the matrix in the LoadMenu function, so that a matrix becomes

[1][0][0][0][0]
[0][2][0][0][0]
[0][0][3][0][0] => [1][2][3][4][5]
[0][0][0][4][0]
[0][0][0][0][5]

while all '0' targets haven't any stimulus type, only 1-5.

That 'sometimes' causes some errors:

'Application'Task::Process: unhandled exception class std::__non_rtti_object (Access violation - no RTTI data!),
terminating Application module.

All i want to know is, if the empty matrix elements are causing the error and if the classifier would be able to handle with the matrix.
On some testruns, the Feature Weights are generated successfully. But the instable behaviour of the programm doesn't please me.
Also i wonder, if this is the right way to make a vector (non matrix) interface or if i should think about doing changes to the classifier.

I'm happy about every weblink, that gives me some knowledge about this ;).

Thank you for attention,
Stefan

mellinger
Posts: 1065
Joined: 12 Feb 2003, 11:06

Re: linear, non matrix P300

Post by mellinger » 12 Jul 2011, 09:07

i tried to change the matrix in the LoadMenu function, so that a matrix becomes

[1][0][0][0][0]
[0][2][0][0][0]
[0][0][3][0][0] => [1][2][3][4][5]
[0][0][0][4][0]
[0][0][0][0][5]

while all '0' targets haven't any stimulus type, only 1-5.
Are you saying that you modified the P3Speller::LoadMenu() function? What do you mean when you say that all '0' targets haven't any stimulus type?
All i want to know is, if the empty matrix elements are causing the error and if the classifier would be able to handle with the matrix.
The error is most likely caused by applying dynamic_cast<>() to an invalid pointer, so make sure your modification to the code does not result in invalid pointers. I could help you more if I knew what modifications you applied to the code.

The error message comes from the Application module, so it has nothing to do with the classifier.
Also i wonder, if this is the right way to make a vector (non matrix) interface or if i should think about doing changes to the classifier.
The classifier works independently of the way how stimuli are presented on screen. In fact, it can be used with the StimulusPresentation module as well as with the P3Speller module.

Hope this helps,
Juergen

OKI
Posts: 18
Joined: 23 Jul 2010, 05:53

Re: linear, non matrix P300

Post by OKI » 13 Jul 2011, 04:49

Hello,

thanks for your reply. I already found the missing dynamic_cast<> that caused my unknown error.

I will have a look on the StimulusPresentation Module. It looks like this is helping me solving all my problems.

When i meant, that all '0' values haven't any stimulus type, i wanted to say, that i don't create them with Stimulus sStimulus = new Stimulus; and i don't add them to the ioStimuli, rowSet and colSet.

Thanks again,
Stefan

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