how to use for loop?

Hi every one briefly, I have i=3:5 and j=1:3 and My equation is how to let i=3 for calculating the first raw and let j changes from 1:3 and for second raw i =4 and let j changes from 1:3 and third raw i =4 and let j changes from 1:3 and third

% Calculate the first row.
i=3
for j=1:3  
  A(i,j)=(A(i-1,1)*A(i-2,j+1)-A(i-1,j+1)*A(i-2,1))/(A(i-1,1))
end

% Calculate the second row
i=4
for j=1:3  
  A(i,j)=(A(i-1,1)*A(i-2,j+1)-A(i-1,j+1)*A(i-2,1))/(A(i-1,1))
end

% Calculate the third row
i=5
for j=1:3  
  A(i,j)=(A(i-1,1)*A(i-2,j+1)-A(i-1,j+1)*A(i-2,1))/(A(i-1,1))
end

Answer 1

[Image Analyst]

Try this:

clc; % Clear command window.
A = magic(5);  % Create some sample data.
% Calculate the first row.
for row = 3 : 5
  for column = 1 : 3
    A(row, column)= ...
      (A(row-1, 1) * A(row-2, column+1) - ...
      A(row-1, column+1) * A(row-2, 1)) / ...
      A(row-1, 1);
  end
end
A  % Print to command window.

[Matlab & Simulink]

Thank you very much Image Analyst

[Image Analyst]

If you want to tall me what you want to do, there may be a vectorized way, or a function to do what you want to do.

Answer 2

[ES]

for i=3:5
for j=1:3
%calculations here.
end
end

Two suggestions: 1. Dont use i and j as variables in matlab as they denote sqrt(-1) 2. Pre allocate arrays before calculation for speed

[Matlab & Simulink]

thanks for replaying

it doesn't work, because I want i=3 for all the first row and j=1:3 and for the second row i = 4 and j=1:3 and so on