Dear Freefem community,

I am trying to solve a scheme with steady nse and my stopping condition for the loop depends on the error between successful iterations. This works quite well when considered l2 norm like below:

u01=0;u02=0;p0=0;

iterror=EXP+1;

real cpu1=clock();

while(iterror>EXP)

{

AH;

iterror=sqrt(int2d(Th)((u01-u1)^2+(u02-u2)^2));

number=number+1;

cout<<“iteration=”<<number<<endl;

u01=u1; u02=u2;p0=p;

}

Bu if I want to use l_infinity norm instead of l2 norm, I got errors like unset. How do I define l infinity norm for “iterror” similar to above sense?

Thanks in advance for ideas