chcksign.m

various matlab programs to slove various problems

function nch=chcksign(dd,bb,x)
[p]=sturm(dd,bb,x); 
n=length(dd); 
nch=0; 
s=0; 
for i=2:(n+1),
    if ((p(i)*p(i-1)) <= 0)
      nch=nch+1; 
    end
    if (p(i)==0)
      s=s+1; 
    end
end
nch=nch-s;
return