[Master Index] [Index for Toolbox]

# smooth_cortex

## (Toolbox/smooth_cortex.m in BrainStorm 2.0 (Alpha))

### Function Synopsis

    [FV,A]=smooth_cortex(arg1,arg2,arg3,arg4)

### Help Text

    SMOOTH_CORTEX - Smoothes tesselation
     function [FV,A]=smooth_cortex(arg1,arg2,arg3,arg4)

     function [smoothedFV,A]=smooth_cortex(FV,vertConnFV,a,nIterations)
     FV is the tesselation to be smoothed
     vertConnFV is the vertices connectivity of the FV tesselation
     a is the smoothing constant
     nIterations is the number of iterations

     function [smoothedFV,A]=smooth_cortex(FV,A,nIterations)
     FV is the tesselation to be smoothed
     A is the sparse smoothing matrix used
     nIterations is the number of iterations

     smoothedFV returned is the smoothed tesselation
     A returned is the sparse smoothing matrix used

     Remarks: smooth_cortex implements the following expression
     smoothedFV.vertices(i,:)=FV.vertices(i,:)+a/N*sum(FV.vertices(neighbor_j,:)-FV.vertices(i,:))
     where FV.vertices(i,:) is the ith vertex, N is the number of neighbors of this vertex, a is a smoothing
     constant, FV.vertices(neighbor_j,:) is jth neighbor of ith vertex. Sum goes over all neighbors of ith
     vertex.

    See also VERTICES_CONNECTIVITY

### Cross-Reference Information

This function is called by

    manage_corticalscouts              C:\BrainStorm_2001\Toolbox\manage_corticalscouts.m
    set_sourceviewing_parameters       C:\BrainStorm_2001\Toolbox\set_sourceviewing_parameters.m

### Listing of function C:\BrainStorm_2001\Toolbox\smooth_cortex.m

    function [FV,A]=smooth_cortex(arg1,arg2,arg3,arg4)
    %SMOOTH_CORTEX - Smoothes tesselation
    % function [FV,A]=smooth_cortex(arg1,arg2,arg3,arg4)
    %
    % function [smoothedFV,A]=smooth_cortex(FV,vertConnFV,a,nIterations)
    % FV is the tesselation to be smoothed
    % vertConnFV is the vertices connectivity of the FV tesselation
    % a is the smoothing constant
    % nIterations is the number of iterations
    %
    % function [smoothedFV,A]=smooth_cortex(FV,A,nIterations)
    % FV is the tesselation to be smoothed
    % A is the sparse smoothing matrix used
    % nIterations is the number of iterations
    %
    % smoothedFV returned is the smoothed tesselation
    % A returned is the sparse smoothing matrix used
    %
    % Remarks: smooth_cortex implements the following expression
    % smoothedFV.vertices(i,:)=FV.vertices(i,:)+a/N*sum(FV.vertices(neighbor_j,:)-FV.vertices(i,:))
    % where FV.vertices(i,:) is the ith vertex, N is the number of neighbors of this vertex, a is a smoothing
    % constant, FV.vertices(neighbor_j,:) is jth neighbor of ith vertex. Sum goes over all neighbors of ith
    % vertex.
    %
    %See also VERTICES_CONNECTIVITY

    %<autobegin> ---------------------- 26-May-2004 11:34:25 -----------------------
    % --------- Automatically Generated Comments Block Using AUTO_COMMENTS ---------
    %
    % CATEGORY: Visualization
    %
    % At Check-in: $Author: Mosher $  $Revision: 10 $  $Date: 5/26/04 10:02a $
    %
    % This software is part of BrainStorm Toolbox Version 2.0 (Alpha) 24-May-2004
    %
    % Principal Investigators and Developers:
    % ** Richard M. Leahy, PhD, Signal & Image Processing Institute,
    %    University of Southern California, Los Angeles, CA
    % ** John C. Mosher, PhD, Biophysics Group,
    %    Los Alamos National Laboratory, Los Alamos, NM
    % ** Sylvain Baillet, PhD, Cognitive Neuroscience & Brain Imaging Laboratory,
    %    CNRS, Hopital de la Salpetriere, Paris, France
    %
    % See BrainStorm website at http://neuroimage.usc.edu for further information.
    %
    % Copyright (c) 2004 BrainStorm by the University of Southern California
    % This software distributed  under the terms of the GNU General Public License
    % as published by the Free Software Foundation. Further details on the GPL
    % license can be found at http://www.gnu.org/copyleft/gpl.html .
    %
    % FOR RESEARCH PURPOSES ONLY. THE SOFTWARE IS PROVIDED "AS IS," AND THE
    % UNIVERSITY OF SOUTHERN CALIFORNIA AND ITS COLLABORATORS DO NOT MAKE ANY
    % WARRANTY, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO WARRANTIES OF
    % MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, NOR DO THEY ASSUME ANY
    % LIABILITY OR RESPONSIBILITY FOR THE USE OF THIS SOFTWARE.
    %<autoend> ------------------------ 26-May-2004 11:34:25 -----------------------

    % ------------------------------ Script Author ---------------------------------
    % Dimitrios Pantazis, Ph.D.

    % ----------------------------- Script History ---------------------------------
    % 11-Apr-2002 DP  Creation
    % 19-May-2004 JCM Fixing a "break" warning notice from Matlab, fixing comments
    % ----------------------------- Script History ---------------------------------

    %choose whether to display bars
    if(~exist('VERBOSE','var')),
        VERBOSE = 1; % default non-silent running of waitbars
    end

    narg = nargin;
    if narg==4
        %assign inputs
        FV=arg1;
        vertConnFV=arg2;
        a=arg3;
        nIterations=arg4;

        nVertices=size(FV.vertices,1);
        if(VERBOSE)
            hwait = waitbar(0,'Creating smoothing matrix...');
            drawnow %flush the display
            step=round(nVertices/10);
        end
        %calculate smoothing matrix
        A=sparse(nVertices,nVertices);
        for i=1:nVertices
            if(VERBOSE)
                if(~rem(i,step)) % ten updates
                    waitbar(i/nVertices,hwait);
                    drawnow %flush the display
                end
            end
            A(i,i)=1-a;
            A(i,vertConnFV{i})=a/length(vertConnFV{i});
        end
        if(VERBOSE)
            close(hwait);
        end
    elseif narg==3
        FV=arg1;
        A=arg2;
        nIterations=arg3;
        nVertices=size(FV.vertices,1);
    else
        disp('Incorrect number of inputs to "smooth_cortex" function'); FV=0; A=0;
        % break;
        % A BREAK statement appeared outside of a loop.  This statement is currently
        % treated as a RETURN statement, but future versions of MATLAB will error
        % instead.
        % JCM fix 19-M1y-2004
        return

    end

    if(VERBOSE)
        hwait = waitbar(0,'Applying smoothing...');
        drawnow %flush the display
        step=round(nIterations/10);
    end
    for i=1:nIterations
        if(VERBOSE)
            if(~rem(i,step)) % ten updates
                waitbar(i/nIterations,hwait);
                drawnow %flush the display
            end
        end
        FV.vertices=A*FV.vertices;
    end
    if(VERBOSE)
        close(hwait);
    end

Produced by color_mat2html, a customized BrainStorm 2.0 (Alpha) version of mat2html on Tue Oct 12 12:05:14 2004
Cross-Directory links are: ON