How to integrate for a data set ?

Dear All,

I want to integrate the following equation

I have the data set of P(hw) and hw. I want to input the value E_g. Data set is given in the excel sheet

Answer 1

[Star Strider]

I have no idea what you are doing.

Try this:

filename = 'solar_spectrum.xlsx';
[D,S,R] = xlsread(filename);
Phw = D(:,1);
hw = D(:,2);
E_g = hw >= 0.5;                                             % Logical Index — Choose ‘E_g’ (Here: 0.5)
S = trapz(hw(E_g), Phw(E_g))

figure
plot(hw, Phw)
hold on
patch([hw(E_g) fliplr(hw(E_g))], [Phw(E_g) fliplr(Phw(E_g))], 'y')
hold off
grid

producing:

S =
     2.0305

The plot shows the approximate area covered by the integration.

Experiment to get the result you want.

[A K M Kamrul Hasan]

How about integration of p^2(hw)d(hw)?