A = readmatrix('name.xls');%I will assume temperature is in the first column and depth in the second column
B = readmatrix('name.xls');
C = readmatrix('name.xls');
D = readmatrix('name.xls');
hold on
plot(A(:,1),A(:,2));
plot(B(:,1),B(:,2));
plot(C(:,1),C(:,2));
plot(D(:,1),D(:,2));
a= gca;
a.XAxisLocation='top';
This should get you going along the righ path.
