Trouble with function using variable inputs.

Hello, I am fairly new to Matlab and am having a little difficulty using the "varargin" statement.

I am trying to create a function which multiplies matrices in a specific way.

The number of inputs will always be some multiple of 3 PLUS 1 (i.e. 4,7,10,13...). Taking as an example an input of 4 variables, (a,b,c,d), I want to do the following operation:

M = [1 0;-1/a 1]*[1 b/c;0 1]*[1 0;-1/d 1];

Putting this into a loop, I would have something like:

M = [1 0;-1/a 1];

N = length(varargin);  %number of input variables

for k = 2:3:N

     b = varargin(k);
     c = varargin(k+1);
     d = varargin(k+2);

     M = M*[1 b/c;0 1]*[1 0;-1/d 1];
  end

However, this does not work. I believe it has to do with the fact that the input variables are not doubles. Does anyone have an advice for me?

Please let me know if I was too vague in my description.

Thanks!

[Image Analyst]

Do you want to do a matrix multiplication or an element-by-element multiplication?

Answer 1

[Jan]

varargin replies a cell, so you need curly braces:

b = varargin{k};
% The same for b and c

Please do not claim only "this does not work". Showing us the complete error message is much more helpful for solvind your problem. Thanks.

[James]

Thanks, Jan! I will make note of that next time I post on here.