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From: Heman on 19 Jul 2010 16:29
"Andy " <myfakeemailaddress(a)gmail.com> wrote in message <i22c7p$5rj$1(a)fred.mathworks.com>...
> Well there is your problem. If h is 1x64, then h' is 64x1. When using the .* element-by-element multiplication, both arrays need to be the same size. So you cannot use .* to multiply the elements of a 1x64 array with the elements of a 64x1 array.

but even if i use the just * and not .* the error remains the same but this time the size is different.

??? Error using ==> mtimes
Inner matrix dimensions must agree.

Error in ==> lms_prof at 45
y(n)=x1*h';

K>> size(x1)

ans =

64 1

K>> size(h)

ans =

1 64
From: Andy on 19 Jul 2010 16:38
"Heman " <kokahemant(a)hotmail.com> wrote in message <i22cje$sl8$1(a)fred.mathworks.com>...
> "Andy " <myfakeemailaddress(a)gmail.com> wrote in message <i22c7p$5rj$1(a)fred.mathworks.com>...
> > Well there is your problem. If h is 1x64, then h' is 64x1. When using the .* element-by-element multiplication, both arrays need to be the same size. So you cannot use .* to multiply the elements of a 1x64 array with the elements of a 64x1 array.
>
> but even if i use the just * and not .* the error remains the same but this time the size is different.
>
> ??? Error using ==> mtimes
> Inner matrix dimensions must agree.
>
> Error in ==> lms_prof at 45
> y(n)=x1*h';
>
> K>> size(x1)
>
> ans =
>
> 64 1
>
> K>> size(h)
>
> ans =
>
> 1 64

Two wrongs don't make a right. You appear to have transposed your x1, since it is not 64x1 instead of 1x64. And you changed .* to just *. But h' is still 64x1, so now you're trying to do a matrix multiplication of a 64x1 with a 64x1. The inner dimensions don't agree, so you get the error you've shown.
From: someone on 19 Jul 2010 16:58
"Heman " <kokahemant(a)hotmail.com> wrote in message <i22cje$sl8$1(a)fred.mathworks.com>...
> "Andy " <myfakeemailaddress(a)gmail.com> wrote in message <i22c7p$5rj$1(a)fred.mathworks.com>...
> > Well there is your problem. If h is 1x64, then h' is 64x1. When using the .* element-by-element multiplication, both arrays need to be the same size. So you cannot use .* to multiply the elements of a 1x64 array with the elements of a 64x1 array.
>
> but even if i use the just * and not .* the error remains the same but this time the size is different.
>
> ??? Error using ==> mtimes
> Inner matrix dimensions must agree.
>
> Error in ==> lms_prof at 45
> y(n)=x1*h';
>
> K>> size(x1)
>
> ans =
>
> 64 1
>
> K>> size(h)
>
> ans =
>
> 1 64

In one of the previous posts you said you were sure the dimensions of h & x1 were the same. It appears they are not. May I suggest that rather than just "randomly" trying various combinations of transposes and multiplies (matrix vs element-by-element) that you take a moment and read the MATLAB Getting Started Guide:

http://www.mathworks.com/access/helpdesk/help/pdf_doc/matlab/getstart.pdf


It is a quick read and is full of information that will be useful to you.
From: Heman on 19 Jul 2010 17:20
Hi Andy & Someone,

Thanks soo much. I have finally resolved the error. It was nothing to do with the y(n) but with this.
if n<= ntaps
x1=[x(n:-1:1) zeros(1,ntaps-n)];
else
x1=x(n:-1:n-ntaps+1);
end

remember Someone, i said i removed the transpose and it worked. But the else part was still having the transpose. I removed this and now there are no errors. But the values of hh are NaN even though e(n), x1 and ibeta are all having values.

y(n)=x1*h';
e(n)=d(n)-y(n);
hh=e(n)*x1/ibeta
h=h+hh;

Thanks Someone for that document.
From: Heman on 19 Jul 2010 17:40
> remember Someone, i said i removed the transpose and it worked. But the else part was still having the transpose. I removed this and now there are no errors. But the values of hh are NaN even though e(n), x1 and ibeta are all having values.
>
> y(n)=x1*h';
> e(n)=d(n)-y(n);
> hh=e(n)*x1/ibeta
> h=h+hh;
>
> Thanks Someone for that document.

Guyz,

I am trying to debug this new problem and i found that the value of y(n) gets to be NaN when n=44, x1 and h have values but i don't understand how the result is NaN.

any suggestions frineds?

thanks
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