p=logspace(log10(2.6403e-007),log10(1),1000);
h=plot(p,p.*log(p))
x=get(h,'Ydata');
y=get(h,'Xdata');
plot(-x,y)
xlabel('|\eta|')
ylabel('|\xi|')
theta=-pi/4*(1-1./(log(y)+1));
figure;
plot(-x,theta)
xlabel('|\eta|')
ylabel('\theta')