if code

Hi guys, I need an help with an if, it's the first time I use it and I am not sure if it works because if I write just & a note appears suggesting to use &&, but if I put && turns an error: ??? Operands to the and && operators must be convertible to logical scalar values.

the code is

    for t=2:time
        dWsim(t,:)=mu0+sigma0.*rndnum(t,:);
        Wsim(t,:)=Wsim(t-1,:)+dWsim(t-1,:);
        B(t,:)=1./((m-1)*(1-Wsim(t,:))).^(1/(m-1));
        sigma(t,:)=sigma0.*((B(t,:)./B(1,:)).^m);
        mu(t,:)=(sigma(t,:).^2).*(m./2.*B(t,:))+mu0.*((B(t,:)./B(1,:)).^m);
        if(uninum(t,1:N)>0.5)&(mu(t,:)*(1/k)>uninum(t,1:N));
            B(t,:)=B(t,:).*(1-k);
        else
           B(t,:)=B(t,:);
        end
    end

Can you please explain me in simple word swhich is the difference between & and &&

Thanks in advance

Gaia

Answer 1

[Jan]

The IF statenment is usually a scalar, otherwise an implicite ALL is performed. But perhaps you want an ANY:

if any(uninum(t,1:N)>0.5) && any(mu(t,:) / k > uninum(t,1:N))

or:

if all(uninum(t,1:N)>0.5 & mu(t,:) / k > uninum(t,1:N))

BTW: "* (1/k)" -> "/k" looks easier.

[gaia buratti]

thabks for the explanation na dfor the suggestion, it does not solve my problem but can be really useful in the future. Btw, thanks to you I understood the mistake, now seems working.

I know about the I was just copying a formula...