I have trouble understanding the command.

I'm having trouble understanding what the command below does, I'd like to know if anyone knows what it does.

for i=1:nset

tty=y(i,:);

index=find(tty>=0);

tx=x(i,index,:);

ty=tty(index);

tpar=mpar(:,i);

command=['[esty seout]=',fun,'(tpar,tx);']; //

eval(command);　

m=length(esty);

predy(i,1:m)=esty;

if(linear == 1);

errory=errory+((esty-ty)*(esty-ty)');

else

findex=find(esty<=0);

esty(findex)=ones(size(findex))/1000000000;

error=20*log10(esty)-20*log10(ty);

errory = errory+error*error';

end

end

I don't know what you are doing with the two sentences in this programme, does anyone know?

command=['[esty seout]=',fun,'(tpar,tx);'];

eval(command);　

[Kaminosono Shougo]

thank you!

You mean you changed the name of the output variable of the function 'fun', that's clear.

[Stephen23]

Do not learn from such badly-written code.

If the code's author had read the Tips section of the EVAL documentation, they would know it is not recommended to include the output arguments in the EVAL call, only the RHS. They could (should) have done that.

And then if they had done a bit more thinking and reading on the topic, they would have known to replace the EVAL with STR2FUNC (which defines a function handle that can be repeatedly called without the performance hit of repeated EVAL calls).

Caecus caeco dux. Sigh.

Answer 1

[Hiro Yoshino]

You should have a good understanding on eval by going through this.

What it does here is that

[esty, seout] = fun(tpar,tx);

It seems there is a function named "fun" somewhere and its arguments are tpar and tx.

[Stephen23]

"It seems there is a function named "fun" somewhere..."

No, we do not know the name of the function. The function's name is certainly stored in a variable named FUN, but with the code shown we do not know the function's name:

command=['[esty seout]=',fun,'(tpar,tx);'];

[Hiro Yoshino]

That function might be an anonymous function (see here).

If this is the case, then it makes sense.

[Kaminosono Shougo]

The code for 'fun' was written separately, thanks!

[Bruno Luong]

@Hiro That function might be an anonymous function

To be precise FUN must be variable or (anonymous-function that return char ouput argument a string/char that stores the name of the 'anonymous' function so it can be form the command called by EVAL.

So there are two different ways of interpreting your "anonymous function".

[Hiro Yoshino]

@Bruno Luong You're right. That was my fault. Sorry guys but it's good to know that you found the "fun" function somewhere.