size(400,200,IgnoreAspect); import graph; import stats; file fin=input("leastsquares.dat").line(); real[][] a=fin.dimension(0,0); a=transpose(a); real[] t=a[0], rho=a[1]; // Read in parameters from the keyboard: //real first=getreal("first"); //real step=getreal("step"); //real last=getreal("last"); real first=100; real step=50; real last=700; // Remove negative or zero values of rho: t=rho > 0 ? t : null; rho=rho > 0 ? rho : null; scale(Log(true),Linear(true)); int n=step > 0 ? ceil((last-first)/step) : 0; real[] T,xi,dxi; for(int i=0; i <= n; ++i) { real first=first+i*step; real[] logrho=(t >= first & t <= last) ? log(rho) : null; real[] logt=(t >= first & t <= last) ? -log(t) : null; if(logt.length < 2) break; // Fit to the line logt=L.m*logrho+L.b: linefit L=leastsquares(logt,logrho); T.push(first); xi.push(L.m); dxi.push(L.dm); } draw(graph(T,xi),blue); errorbars(T,xi,dxi,red); crop(); ylimits(0); xaxis("$T$",BottomTop,LeftTicks); yaxis("$\xi$",LeftRight,RightTicks);