Efficient Matrix Multiplication with Nested Functions for MATLAB Homework

[Feodalherren]

Homework Statement

Homework Equations

[/B]

----------------------
[FONT=Courier New]function [C]=mymatmult(A,B)
[L1 C1]=size(A);
[L2 C2]=size(B);

if C1 ~= L2
  error('dimension mismatch');
end %if ERROR

C=zeros(L1,C2);
for i=1:L1
  for j=1:C2
  C(i,j)=A(i,:)*B(:,j);
  end %in for
end %out for
end %function[/FONT]
------------------------------
[FONT=Courier New]function B = MyTranspose(A)

[rows cols] = size(A);

B=zeros(cols,rows);

for i=1:rows
  for j=1:cols
  B(j,i) = A(i,j)+B(j,i);
  end %in for
end %out fo

end %function[/FONT]
------------------------

The Attempt at a Solution

function [A1, A2] = MyTransposeProduct(A)

%place your nested function here--------------------------
  function B = MyTranspose(A)

  [rows, cols] = size(A);

  B=zeros(cols,rows);

  for i=1:rows
  for j=1:cols
  B(j,i) = A(i,j)+B(j,i);
  end %end in for
  end %end out for
  end %end in funct

%end nested function------------------------------------------

%second nested function---------------------------------------

  function [C]=mymatmult(A,B)
  [L1, C1]=size(A);
  [L2, C2]=size(B);

  if C1 ~= L2
  error('dimension mismatch');
  end %if ERROR

  C=zeros(L1,C2);
  for i=1:L1
  for j=1:C2
  C(i,j)=A(i,:)*B(:,j);
  end %in for
  end %out for

  A1=mymatmult(A,MyTranspose(A));
  A2=mymatmult(MyTranspose(A),A);  end %function

%end second nested function-----------------------------------

end % main function

But nothing happens when I run this code. No errors and no result...

 

[DrClaude]

Look where you put the code to calculate A1 and A2.

Also, I don't understand why you wrote MyTranspose that way. Why does B appear on both sides of the assignment?

 

[jedishrfu]

By the way, I adjusted your post using code tags for readability.

Here's some info on nested functions that may help:

http://www.mathworks.com/help/matlab/matlab_prog/nested-functions.html?s_cid=srchtitle

Also I would suggest adding proper indents to the body of your functions for readability if you can.

 

[Feodalherren]

Nevermind, figured it out. Thanks!