Re: What should I do to fix "warning: implicit conversion from real matrix to real scalar"?

[Carlo de Falco]

On 8 Jul 2009, at 20:06, John B. Thoo wrote:

> Hi, Carlo.  Thanks for the tip.  So, then, is using "trapz" in the  
> following way my only recourse to find  \int H(u(:,t)) dx  for some  
> function  H(x)  where  u(x,t)  is a matrix?

It is not the only option but it is the safest bet if you
don't know anything else about your data...

> %%--------begin energy.m---------
> clear all
>
> global u;
> load ht_tf8M160ord9visc01.mat;
>
> function y = h (x)
> global u;
>
>  U = u(:,5);
>  y = (U.^2).';
>
> endfunction
>
> trapz (x, h (x))
> %%---------end energy.m----------

there's no reason to define a function for calling trapz, you can just  
do

%%--------begin energy.m---------
load ht_tf8M160ord9visc01.mat
trapz (x, u(:,5).^2)
%%---------end energy.m----------


> Or is there a way I can use either "quad" or "quadl"?  Thanks again.

there is no point in using quad or quadl in this case.
c.