Matrix multiplication error in conjugate transpose

I get Incorrect dimensions for matrix multiplication error in step 4, line 75 and furthur, what can I do?

%Defining input parameters
function [chp] = dualaccumulatorahk(d,l,N,T,S1,S2,U1,V1,w)
%d is decay and is mostly considered as 1 in this model and would be open to more values in the extended version
%l is Lambda, N is the number of simulations of the deliberative process, T is the time range
%S1 is payoff matrix where self is the row player and S2 is payoff matrix where other is row player
%U1 and V1 are salience biases of players 1 and 2, respectively and in the
%absence of bias will set to 99
% w is trembling hand noise which is 0 here

%example: considering a two-strategy hide-and-seek game with player 1 as a hider and player 2 as a seeker we have:
%0,.5    1,0
%1,0    0,.5  as a full payoff matrix and the aforementioned parameters are:

d = 1;
S1 =[100,60,62,64;60,62,66,70];
S2 =[70,69,66,10;10,40,66,68];
l = 1;
T = 30; 
U1 = 99;
V1 = 99;
N = 10000;
w = 0;

% Step 0 & 1

% possible number of strategies per player
ns1 = length(S1(:,1));
ns2 = length(S2(:,1));

chp = zeros(ns1,N)

% set a start for activation biases 
if U1 == 99
    U1 = zeros(1,ns1);
end
if V1 == 99
    V1 = zeros(1,ns2);
end

%initiation of N simulations

for i = 1:N
    
    U = zeros([ns1,T+1]); %as in the first column the time is 0
    V = zeros([ns2,T+1]);
    
    
    %Step 2: Leave initial preference and beliefs at 0
    
    U(:,1) = U1; 
	V(:,1) = V1;
    
    for t = 2:T+1
        
    %Step 3: Sample one of the opponent's strategies
    A = V(:,t-1) + V1';
    P = exp(1*A)/sum(exp(1*A));
    
    %See whether the definition of P is legit
    
    if sum(isfinite(P)) < ns2
        P = zeros(1,ns2)';
        for k = 1:ns2
            if A(k)== max(A)
                P(k) = 1;
            end
        end
        P = P/sum(P);
    end
    
 % Step 4: Update activations in preference node
 
   U(:,t);
   d*U(:,t-1);
   S1*mnrnd(1,P)';
   normrnd(0,w,ns1,1)
   U1
   U(:,t) = d*U(:,t-1) + S1*(mnrnd(1,P')') + normrnd(0,w,ns1,1);
  
 % Step 5: Sample one of the decision maker’s own strategies
 
  A = U(:,t) + U1';
  P = exp(l*A)/sum(exp(l*A));
		
		if sum(isfinite(P)) < ns1	
			P =zeros(1,ns1)';			
			for k = 1:ns1
				if A(k) == max(A)
					P(k) = 1;
				end
			end				
			P = P/sum(P);			
        end
        
   % Step 6: Update activations in belief node
   
   %	V(:,t) = d*V(:,t-1) + S2*(mnrnd(1,P')') + normrnd(0,w,ns2,1);
    
    end
    

   % Step 7 & 8: making decision
   for k = 1:ns1
		if U(k,T+1) == max(U(:,T+1))
			chp(k,i) = 1;
		end
	end
	chp(:,i) = chp(:,i)/sum(chp(:,i));
		
end

% Step 9: Getting the average choice probabilities for each of the decision maker’s strategies
for k = 1:ns1
	chp2(k) = mean(chp(k,:));
end
    
     
    

    

[Geoff Hayes]

Amir - please copy and paste the full error message to this question. Also, what are the inputs that you are using? You can attach them (in a *.mat file) to this question.

[Amir Hossein K]

Hi Geoff - I get the following error:

Error using *

Incorrect dimensions for matrix multiplication. Check that the number of columns in the first matrix matches the number of rows in the second matrix. To perform elementwise

multiplication, use '.*'

Error in dualaccumulatorahk (line 75)

S1*mnrnd(1,P)';

My inputs will be entered manually as you can see in function [chp] but I have attached one as an example.

[Geoff Hayes]

Amir - the problem is that you are trying to multiply two matrices with incompatible dimensions. S1 is a 2x4 array and mnrnd(1,P)' is a 2x1. Which one of these matrices is incorrect? Should P be a 1x4 array so that mnrnd(1,P)' is a 4x1?

Also, in this code

   U(:,t);
   d*U(:,t-1);
   S1*(mnrnd(1,P)');
   normrnd(0,w,ns1,1)
   U1

there are no assignments to any local variables. Is this code really needed or are you missing something?

[Amir Hossein K]

Geoff - I tried to write the codes using the following pseudocode and I think the dimensions are correct and even if I ignore the codes above (which are related to activation of preference node), I'll have the same problem in the next line. I also have a problem in defining a range for T which is between 0-30.

[Geoff Hayes]

Amir - hopefully someone else will be able to comment on this. It isn't all that clear to me how the above pseudocode translates to your code.