Description: SAMentropy computes the rank vector entropy (RVE) for continuous data and outputs a 3D+time image. It does not compute event-related RVE (for which see, SAM3d/SAM3dc, SAM4d/SAM4dc, or SAMers/SAMersc). SAMentropy is intended for use in connectivity studies of the correlation of the envelope of power among voxels -- e.g., by using ICA or the AFNI, function "Instacorr".
SAMentropy applies the beamformer coefficients to the filtered MEG data (specified by ImageBand) to compute the estimated source time-series. It then transforms the voxel time series to a rank vector entropy time-series for an embedding space of 4 or 5 dimensions to obtain the envelope of power. This is written to the corresponding voxel.
Usage:
SAMentropy -r <dataset_name> -m <parameter_file_name> -v
The -r flag is followed by the dataset name (with or without the .ds suffix). The -m flag is followed by the parameter file name without the .param suffix. The -v argument specifies verbose output — else SAMentropy works silently.
Optional flags are:
The required parameter file keywords for SAMentropy are:
Optional keywords include:
Example parameters for imaging rank vector entropy for broad-band activity (4-150 Hz) in a 4-dimensional embedding space, in Taliarach space on an 8mm grid:
NumMarkers | 0 | ||
CovBand | 4.0 | 150.0 | |
ImageBand | 4.0 | 150.0 | |
XBounds | -12 | 12 | |
YBounds | -9 | 9 | |
ZBounds | -2 | 15 | |
ImageStep | 0.5 | ||
ImageFormat | TLRC | 8.0 | |
Mask | /data2/Mask8mm.nii | ||
ImageMetric | RankVectorEntropy | 0.5 | 4 |
CovType | GLOBAL | ||
MRIDirectory | /data1/mri | ||
ImageDirectory | /data1/Rest/Images | ||
TimeStep | 0.01 | ||
BaselineRemoval | BYVOXEL |