Integral of experimental data

Hi, I'm tryng to solve an integral like this:

I have two data columns about variables P and V, both defined as function of an angle teta (-360<teta<360). How can I integrate this curve?

[Andrew Newell]

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Answer 1

[Roger Stafford]

Using 'g' in place of 'gamma', do this:

   Q = (g*trapz(V,P)+trapz(P,V))/(g-1);

or if you want the cumulative integral, replace each 'trapz' by 'cumtrapz'.

This assumes that P and V are vectors of the same length with corresponding elements given by the same value of 'theta'.