How to calculate the area under curve?

I have attached a curve in which x axis is time and y axis is amplitude. How to calculate the area under this curve.Please suggest me.

Answer 1

[Torsten]

area_under_curve= trapz(x,y)

[AS]

I am little confused with area_under_curve= trapz(x,y) because if I wrote area_under_curve= trapz(y), then answer is 32.600 but if I wrote area_under_curve= trapz(x,y) then answer is 1.8051e+03.

So, please suggest me which one is correct.

[Torsten]

If the spacings between the x-values is 1, you can use trapz(y), else you must use trapz(x,y).

The fact that the two results are different indicates that the spacing is different from 1 in your case.

[AS]

Thank you so much.