function [Fcontmat,rcontmat,MScont,MScs,dfcs,pcontmat]=repeatcon(repeatmat,weights);

%	Calculates F-value for trend analysis for a repeated measures factor and
%	returns values in Fcontmat. Effect size estimate r(contrast) according to
%	Rosenthal et al. are returned in rcontmat. Neither the F-value nor the
%	r(contrast) gives you information about the direction of the trend!
%	repeatmat: is a data array arranged such that channels/sensors etc. 
%				are represented as rows, subjects as columns and conditions
%				in the 3. dimension. Arrange the conditions in such a way that
%				they correspond to the trend.Function sort4trend then arranges it
%				in an appropriate way for contrast analysis.
%	weights: always have to sum up to zero. Following weights for orthogonal
%				contrasts (linear, quadratic, cubic) are suggeste by Rosenthal 
%				& Rosnow (1985).
%			2 conditions:
%				lin: [-1 1]
%			3 conditions:
%				lin: [-1 0 1], quad: [1 -2 1]
%			4 conditions:
%				lin: [-3 -1 1 3], quad: [1 -1 -1 1], cub: [-1 3 -3 1]
%			5 conditions:
%				lin: [-2 -1 0 1 2], quad: [2 -1 -2 -1 2], cub: [-1 2 0 -2 1]
%			6 conditions:
%				lin: [-5 -3 -1 1 3 5]
%				quad: [5 -1 -4 -4 -1 5]
%				cub: [-5 7 4 -4 -7 5]
%			7 conditions:
%				lin: [-3 -2 -1 0 1 2 3] 	
%				quad: [5 0 -3  -4 -3 0 5]
%				cub: [-1 1 1 0 -1 -1 1]
%			8 conditions:
%				lin: [-7 -5 -3 -1 1 3 5 7]
%				quad: [7 1 -3 -5 -5 -3 1 7]
%				cub: [-7 5 7 3 -3 -7 -5 7]
%			9 conditions:
%				lin: [-4 -3 -2 -1 0 1 2 3 4]
%				quad: [28 7 -8 -17 -20 -17 -8 7 28]
%				cub: [-14 7 13 9 0 -9 -13 -7 14]
%			10 conditions:
%				lin: [-9 -7 -5 -3 -1 1 3 5 7 9]
%				quad: [6 2 -1 -3 -4 -4 -3 -1 2 6]
%				cub: [-42 14 35 31 12 -12 -31 -35 -14 42]
%
%	Function created according to R. Rosenthal & R. Rosnow (1985). Contrast
%	analysis: Focused comparisons in the analysis of variance. Cambridge: CUP.
%
%	Further resource: R. Rosenthal, R. Rosnow & D.B. Rubin (2000). Contrasts
%	and effect sizes in behavioral research: a correlational approach. Cambridge:
%	CUP.


%   This software is protected by german copyright and international treaties.             
%   Copyright 2004 Nathan Weisz, Markus Junghöfer & Peter Peyk. All Rights Reserved.                     
%                                                                                          
%   THIS SOFTWARE AND DOCUMENTATION IS PROVIDED "AS IS," AND COPYRIGHT HOLDERS MAKE        
%   NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO,    
%   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT THE USE    
%   OF THE SOFTWARE OR DOCUMENTATION WILL NOT INFRINGE ANY THIRD PARTY PATENTS, COPYRIGHTS,
%   TRADEMARKS OR OTHER RIGHTS. COPYRIGHT HOLDERS WILL NOT BE LIABLE FOR ANY DIRECT,       
%   INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF ANY USE OF THE SOFTWARE      
%   OR DOCUMENTATION. 



%hier Vp als Reihe, Bedingung als Spalte

[repeatmat]=sort4trend(repeatmat);

[m,n,o]=size(repeatmat);

for j = 1:o
    
    %Berechnung von Mean square contrast
    sumrep = sum(repeatmat(:,:,j));%summierte ueber Vps
    
    L2 = (sum(sumrep.*weights)).^2;
    
    MScont = L2/(m*sum(weights.^2));
    
    %Corrections of data matrix
    
    %for Grand Mean
    
    corGM=repeatmat(:,:,j) - mean(mean(repeatmat(:,:,j)));
    
    %for row effect
    
    rowef=mean(corGM,2);
    
    [m,n]=size(repeatmat(:,:,j));
    
    for i =1:n
        corGMR(1:m,i) = corGM(1:m,i)-rowef;
    end
    
    %for column effect
    
    colef = mean(corGMR);
    
    for i =1:m
        corGMRC(i,1:n)=corGMR(i,1:n)-colef;
    end
    
    %sum of squares for condition x subjects
    %this is used as error term for calculation of F. one also could
    %calculate seperate error terms for each trend type. see Rosnow &
    %Rosenthal for details. the approach here is sufficient in most cases.
    
    SScs = sum(sum(corGMRC.^2));
    
    dfcs = m*(n-1);
    
    MScs = SScs/dfcs;
    
    Fcont = MScont/MScs;
    
    Fcontmat(j,1) = Fcont; 
    
    %Calculat effect size r(contrast). Use of df of pooled error term will lead
    %to underestimation of effect size. df has to be divided by factor number
    %of conditions minus one.
    
    rcont=sqrt(Fcont/(Fcont+(dfcs/(n-1))));
    
    rcontmat(j,1) = rcont;
    pcontmat = 1-fcdf(Fcontmat,1,dfcs);
    
end

sprintf('concerning F: degrees of freedom are 1,%d',dfcs)
