Check the final execution group in the attached, which initialises and fills a 3-column matrix.
Column1 contains T__1 values (I arbitrarily picked 1..10 - any range/spacing would be trivial to arrange).
Column2 contains T__1s values (I arbitrarily picked 1.5..10.5 - any range/spacing would be trivial to arrange).
Column3 contains the corresponding values of h__1(T__1, T__1s)
NB I tried a few ways of selecting T__1 and T__1s values, but always ended up with some complex entries in column1. I suggest you try this code with values you consider appropriate for T__1 and T__1s. You may be able to come up with some combination which does not result in complex values for h__1().