dimension mismatch in for loop

Hi, all I would like to save the data from RM to RMS. however there is a dimension error within code. To use for loop i would like to put into data from RM matrix to RMS matrix. Do you have any idea how to match dimension and to save the data to RMS matrix. cheers,

%%%%%%%%%%%%%%%%%%%%%%%%%%% test %%%%%%%%%%%%%%%%%%%%%%%%%%

    M = rand(332,7);  
    x= rand(332,1);  
    y= rand(332,1);  
    z= rand(332,1);
    r = (x.^2 + y.^2 + z.^2).^0.5;

   Bx = rand(332,1);
   By = rand(332,1);
   Bz = rand(332,1);
   Bt = ((Bx).^2 + (By).^2 + (Bz).^2).^0.5;

    mu = 10^(-7);
   rad = pi/180;
    nM = NaN(332,5); 
    RM = NaN(1,4);
    RMS = zeros(9999);

for i = 1:332

   nBx = (-mu.*(M(i,4)).*(sin(M(i,6).*rad)).*(cos(M(i,7).*rad))./(r.^3) + 3.*mu.*((M(i,4)).*(sin(M(i,6).*rad)).*(cos(M(i,7).*rad)).*x + (M(i,4)).*(sin(M(i,6).*rad)).*(sin(M(i,7).*rad)).*y + (M(i,4)).*(cos(M(i,6).*rad)).*z).*x./(r.^5));
   nBy = (-mu.*(M(i,4)).*(sin(M(i,6).*rad)).*(sin(M(i,7).*rad))./(r.^3) + 3.*mu.*((M(i,4)).*(sin(M(i,6).*rad)).*(cos(M(i,7).*rad)).*x + (M(i,4)).*(sin(M(i,6).*rad)).*(sin(M(i,7).*rad)).*y + (M(i,4)).*(cos(M(i,6).*rad)).*z).*y./(r.^5));
   nBz = (-mu.*(M(i,4)).*(cos(M(i,6).*rad))./(r.^3) +                     3.*mu.*((M(i,4)).*(sin(M(i,6).*rad)).*(cos(M(i,7).*rad)).*x + (M(i,4)).*(sin(M(i,6).*rad)).*(sin(M(i,7).*rad)).*y + (M(i,4)).*(cos(M(i,6).*rad)).*z).*z./(r.^5));

   nx = nBx .* 1.0e+9;
   ny = nBy .* 1.0e+9;
   nz = nBz .* 1.0e+9; 
   nt = (nx.^2 + ny.^2 + nz.^2).^0.5;

    Rx = (Bx - nx).^2 ;
    Ry = (By - ny).^2 ;
    Rz = (Bz - nz).^2 ;
    Rt = (Bt - nt).^2;

    nM = [Rx,Ry,Rz,Rt]; 

   RSx = (sum(nM(:,1))/332)^0.5;
   RSy = (sum(nM(:,2))/332)^0.5;
   RSz = (sum(nM(:,3))/332)^0.5;
   RSt = (sum(nM(:,4))/332)^0.5;

   RM = [RSx,RSy,RSz,RSt];

   RMS(i,:)= RM;   % <--  Subscripted assignment dimension mismatch.

end

%%%%%%%%%%%%%%%%%%%%%%%%%%% test %%%%%%%%%%%%%%%%%%%%%%%%%%

Answer 1

[Walter Roberson]

You appear to be trying to store 4 columns at a time into an array that has 9999 columns. Remember when you use : as a subscript you are writing over the entire row or column so the length of the data has to match.

[JungKyu Lee]

i changed them RMS = zeros(9999) to RMS = zeros(332,4)

and

   RM = [RSx,RSy,RSz,RSt];
   RMS(i,:)= RM

to

RMS(i,1)= RM(1,1);
 RMS(i,2)= RM(1,2);
 RMS(i,3)= RM(1,3);
 RMS(i,4)= RM(1,4);

but i do not understand the reason!!

[Walter Roberson]

A(1, :) = B does not mean "store the data from B into row 1 of A, starting from column 1 and going for as many columns as needed according to the size of B"

Instead, A(1,:) means A(1,1:end) which means A(1,1:size(A,2)). In other words it is asking to overwrite all of row 1 of A, and if there is the wrong amount of data available to be written then that is an error.