Riemann sum to find the area between two curves

I'm trying to find the Riemann sum of the area between two curves as shown in the diagram below. Xn is rescaled and a new data set is the difference between Xc and rescaled data. I need to take the Riemann sum over the region between these two (Xc and (Xn rescaled) data).

I have coded that as below, but I'm not sure how to take the Riemann sum of these data poionts.

phi = linespace(1,100,1)%array of 100 values
sol_n=xn.sol_all;  %this is a 1500*100 data set
sol_c=xc.sol_all; %this is a 1500*100 data set

for i =1:length(phi)
    Xn_new= (sol_n(:,i)).*((sol_c(end,i))./(sol_n(end,i))); %Rescaling  Xn
    Xc_new = sol_c(:,i);
    Data = Xc_new- Xn_new;

end

Your help is greatly appreciated.

Answer 1

[Cameron]

x = 0:0.01:1; %some x data
s1 = x./(x+exp(1-7*x)); %some y data
s2 = x./(x+exp(1-10*x)); %some other y data
plot(x,s1,'b',...
    x,s2,'r')

sumS1 = trapz(x,s1); %trapezoidal integration 
sumS2 = trapz(x,s2); %trapezoidal integration
sumBetween = sumS2 - sumS1 %subtract the two for answer

sumBetween = 0.0742

[UserCJ]

@Cameron Thank you very much foryour help. That worked well!