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help > Extract first principal component only (PCA)
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Mar 15, 2017 10:03 AM | Isabel Berwian
Extract first principal component only (PCA)
Hello Alfonso
I have a short question. I am writing a batch script and I would like to use the first principal component of my ROI only.
In the conn_batch_help document it says:
dimensions : rois.dimensions{nroi} number of ROI dimensions - # temporal components to extract from ROI [1] (set to 1 to extract the average timeseries within ROI voxels; set to a number greater than 1 to extract additional PCA timeseries within ROI voxels; set to 0 to compute a weighted sum within ROI voxels (ROI mask values are interpreted as weights))
From the description it is unclear to me, to which number I need to set it to only get the first principal component?
A short advice would be greatly appreciated!
Isabel
I have a short question. I am writing a batch script and I would like to use the first principal component of my ROI only.
In the conn_batch_help document it says:
dimensions : rois.dimensions{nroi} number of ROI dimensions - # temporal components to extract from ROI [1] (set to 1 to extract the average timeseries within ROI voxels; set to a number greater than 1 to extract additional PCA timeseries within ROI voxels; set to 0 to compute a weighted sum within ROI voxels (ROI mask values are interpreted as weights))
From the description it is unclear to me, to which number I need to set it to only get the first principal component?
A short advice would be greatly appreciated!
Isabel
Apr 5, 2017 02:04 PM | Isabel Berwian
RE: Extract first principal component only (PCA)
Dear Conn-Users
I have a short question. I am writing a batch script and I would like to use the first principal component of my ROI only.
In the conn_batch_help document it says:
dimensions : rois.dimensions{nroi} number of ROI dimensions - # temporal components to extract from ROI [1] (set to 1 to extract the average timeseries within ROI voxels; set to a number greater than 1 to extract additional PCA timeseries within ROI voxels; set to 0 to compute a weighted sum within ROI voxels (ROI mask values are interpreted as weights))
From the description it is unclear to me, to which number I need to set it to only get the first principal component?
A short advice would be greatly appreciated!
Isabel
I have a short question. I am writing a batch script and I would like to use the first principal component of my ROI only.
In the conn_batch_help document it says:
dimensions : rois.dimensions{nroi} number of ROI dimensions - # temporal components to extract from ROI [1] (set to 1 to extract the average timeseries within ROI voxels; set to a number greater than 1 to extract additional PCA timeseries within ROI voxels; set to 0 to compute a weighted sum within ROI voxels (ROI mask values are interpreted as weights))
From the description it is unclear to me, to which number I need to set it to only get the first principal component?
A short advice would be greatly appreciated!
Isabel