cosmo vol grid convert hdrΒΆ

function ds_conv=cosmo_vol_grid_convert(ds,varargin)
% convert between volumetric (fmri) and grid-based (meeg source) dataset
%
% ds_conv=cosmo_vol_grid_convert(ds[,direction])
%
% Inputs:
%   ds              dataset struct, either in fmri or meeg source form
%   direction       (optional) conversion direction, either
%                   - 'tovol' : convert to a volumetric (fmri) dataset
%                   - 'togrid': convert to a source (meeg) dataset
%                   If this option is omitted, then 'tovol' is selected if
%                   ds is an meeg source dataset, and 'togrid' otherwise
%
% Output:
%   ds_conv         dataset in volumetric or source format
%
% Example:
%     ds=cosmo_synthetic_dataset('size','normal');
%     % feature attributes are i, j, k
%     cosmo_disp(ds.fa,'edgeitems',2);
%     %|| .i
%     %||   [ 1         2  ...  2         3 ]@1x30
%     %|| .j
%     %||   [ 1         1  ...  2         2 ]@1x30
%     %|| .k
%     %||   [ 1         1  ...  5         5 ]@1x30
%     % fmri dataset has .a.vol
%     cosmo_disp(ds.a,'edgeitems',2);
%     %|| .fdim
%     %||   .labels
%     %||     { 'i'
%     %||       'j'
%     %||       'k' }
%     %||   .values
%     %||     { [ 1         2         3 ]
%     %||       [ 1         2 ]
%     %||       [ 1         2         3         4         5 ] }
%     %|| .vol
%     %||   .mat
%     %||     [ 2         0         0        -3
%     %||       0         2         0        -3
%     %||       0         0         2        -3
%     %||       0         0         0         1 ]
%     %||   .dim
%     %||     [ 3         2         5 ]
%     %||   .xform
%     %||     'scanner_anat'
%     %
%     % convert to get grid representation
%     ds_grid=cosmo_vol_grid_convert(ds,'togrid');
%     % feature attribute is pos
%     cosmo_disp(ds_grid.fa,'edgeitems',2);
%     %|| .pos
%     %||   [ 1        11  ...  20        30 ]@1x30
%     % meeg source dataset has no .a.vol
%     cosmo_disp(ds_grid.a,'edgeitems',2);
%     %|| .fdim
%     %||   .labels
%     %||     { 'pos' }
%     %||   .values
%     %||     { [ -1        -1  ...  3         3
%     %||         -1        -1  ...  1         1
%     %||         -1         1  ...  5         7 ]@3x30 }
%     %
%     % convert it back to a format identical to the input
%     ds_vol=cosmo_vol_grid_convert(ds_grid,'tovol');
%     %
%     isequal(ds.fa,ds_vol.fa)
%     %|| true
%     isequal(ds.a.vol.mat,ds_vol.a.vol.mat)
%     %|| true
%     isequal(ds.a.fdim,ds_vol.a.fdim)
%     %|| true
%
% Notes:
%   - when ds is an meeg source dataset, it is required that the positions
%     can be placed in a regular grid
%
% #   For CoSMoMVPA's copyright information and license terms,   #
% #   see the COPYING file distributed with CoSMoMVPA.           #