Syntax to multiply 10 different 2 by 2 matrices sequentially in matlab

Please I need help with syntax to multiply ten 2 by 2 matrices i.e T = A1*A2*A3*A4*A5*A6*A7*A8*A9*A10 in matlab

[Image Analyst]

"Matrix" multiplication, or "element-by-element" multiplication?

[Segun Emmy]

Sir I need syntax for element by element multiplication called from the output of a for loop manipulation. Say T is the output that contains ten different 2 by 2 matrix from the for loop. How do i get their product in this form: T = T1*T2*T3*...* TN TO obtain a SINGLE 2 by 2 answer Thanks

Answer 1

[Andrei Bobrov]

A = cat(3,A1,A2,A3,A4,A5,A6,A7,A8,A9,A10);
s = size(A,3);
out = A(:,:,1);
for jj = 2:s
    out = out*A(:,:,jj);
end

or

A = {A1,A2,A3,A4,A5,A6,A7,A8,A9,A10};
out = A{1};
for jj = 2:numel(A)
    out = out*A{jj};
end

or for "element by element" multiplication

A = cat(3,A1,A2,A3,A4,A5,A6,A7,A8,A9,A10);
out = prod(A,3);

[Segun Emmy]

Thanks for your quick response please what code do I include if this ten 2 by 2 matrices are outputs from a for loop to reference them or call them from the output "A" instead of listing them as A1,A2,A3 etc

[Walter Roberson]

Don't let them be outputs from a for loop. Reprogram the for loop.

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

Answer 2

[Image Analyst]

For element by element multiplication, I believe this should work:

T = A1.*A2.*A3.*A4.*A5.*A6.*A7.*A8.*A9.*A10

If the A's are of class integer, you'll have to watch out if they exceed the max value, intmax('uint8') or intmax('uint16'), or else your product will be clipped. Cast to double before multiplication if that's the case.