%% Crossvalidation searchlight
%
% # For CoSMoMVPA's copyright information and license terms, #
% # see the COPYING file distributed with CoSMoMVPA. #
%% Define data
%
config=cosmo_config();
data_path=fullfile(config.tutorial_data_path,'ak6','s01');
% In this exercise, output (NIFTI files) will be written to this directory
output_data_path=config.output_data_path;
data_fn=fullfile(data_path,'glm_T_stats_perrun.nii');
mask_fn=fullfile(data_path,'brain_mask.nii');
ds=cosmo_fmri_dataset(data_fn,'mask',mask_fn,...
'targets',repmat(1:6,1,10),...
'chunks',floor(((1:60)-1)/6)+1);
% remove constant features (due to liberal masking)
ds=cosmo_remove_useless_data(ds);
%% Neighborhood definition
% Use a searchlight with a more-or-less constant number of voxels,
% both near the edges of the brain and in the center of the brain.
nvoxels_per_searchlight=100;
% Define a spherical neighborhood with approximately
% 100 voxels around each voxel using cosmo_spherical_neighborhood,
% and assign the result to a variable named 'nbrhood'
%%%% >>> Your code here <<< %%%%
%% Define the measure as
% define the measure as cosmo_crossvalidation_measure
%%%% >>> Your code here <<< %%%%
% Define measure arguments.
% Ideally we would like to use nfold_partitioner (and you probably
% want to do this for a publication-quality), but this takes quite long.
% Instead, we take a short-cut here and use an
% odd-even partitioning scheme that has only one fold (test on odd chunks,
% test on even) using cosmo_oddeven_partitioner.
measure_args=struct();
% As the 'partitions' argument, use an odd-even partitioner
%%%% >>> Your code here <<< %%%%
% Use cosmo_classify_lda as classifier argument for the measure
%%%% >>> Your code here <<< %%%%
%% Run searchlight
% Using the neighborhood, the measure, and the measure's arguments, run the
% searchlight using cosmo_searchlight. Assign the result to a variable
% named 'ds_cfy'
%%%% >>> Your code here <<< %%%%
%% Visualize and store the results in a NIFTI file
% Visualize the results using cosmo_plot_slices
cosmo_plot_slices(ds_cfy);
% Set output filename
output_fn=fullfile(output_data_path,...
sprintf('lda_odd-even_accuracy_d%.0fvx.nii',nvoxels_per_searchlight));
% Write output to a NIFTI file using cosmo_map2fmri
%%%% >>> Your code here <<< %%%%
