There seems to be a bug in Xsteam when T_hs is called in a certain regime. I believe this occurs in the saturated regime near h = 1500 kJ/kg between s = 3.17 and 3.18 kJ/kg
% Run this code in a folder with Xsteam.m and you will see a flaw with 'T_hs'closeall;clearall;clc;%T_hs Temperture as a function of enthalpy and entropycontours=0forh=300:400:1900contours=contours+1;hsa=linspace(0,8,100);%N=size(sa,2);Ta=zeros(N,1);forn=1:NTa(n)=XSteam('T_hs',h,sa(n));endplot(sa,Ta);holdontitle('Trouble with T\_hs at h=1100: Plots for h = 300, 700, 1100, 1500, 1900');%legend('h=constant');xlabel('s=entropy (kJ/kg)');ylabel('T=temperature (Celsius)');end