SurfStatStand

Standardizes by subtracting the global mean, or dividing by it.

 Usage: [ Y, Ym ] = SurfStatStand( Y [,mask [,subtractordivide] ] );

 Y                = n x v matrix of data, v=#vertices.
 mask             = 1 x v, 1=inside, 0=outside, v=#vertices.
                  = ones(1,v) by default.
 subtractordivide = 's' for Y=Y-Ym (default) or 'd' for Y=(Y/Ym-1)*100.

 Y  = n x v matrix of standardized data.
 Ym = n x 1 vector of mean(Y in mask).

0001 function [ Y, Ym ] = SurfStatStand( Y, mask, subtractordivide);
0002 
0003 %Standardizes by subtracting the global mean, or dividing by it.
0004 %
0005 % Usage: [ Y, Ym ] = SurfStatStand( Y [,mask [,subtractordivide] ] );
0006 %
0007 % Y                = n x v matrix of data, v=#vertices.
0008 % mask             = 1 x v, 1=inside, 0=outside, v=#vertices.
0009 %                  = ones(1,v) by default.
0010 % subtractordivide = 's' for Y=Y-Ym (default) or 'd' for Y=(Y/Ym-1)*100.
0011 %
0012 % Y  = n x v matrix of standardized data.
0013 % Ym = n x 1 vector of mean(Y in mask).
0014 
0015 if nargin<2 | isempty(mask)
0016     mask=logical(ones(1,size(Y,2)));
0017 end
0018 if nargin<3
0019     subtractordivide = 's';
0020 end
0021 Ym=mean(Y(:,mask),2);
0022 for i=1:size(Y,1)
0023     if subtractordivide(1) == 's'
0024         Y(i,:)=Y(i,:)-Ym(i);
0025     else
0026         Y(i,:)=(Y(i,:)/Ym(i)-1)*100;
0027     end
0028 end
0029 
0030 return
0031 end
0032     
0033     
0034     
0035