how to calculate the integral of the area difference between these two curves?

Hi,

I need to calculate the integral of the area in green, how do i do that on MATLAB?

I use trapz to integrate.

Thank you

Answer 1

[infinity]

Hello,

Here is my suggestion that can be done by trapz.

First, you use trapz to calcultate integral of "blue" line with dB from 60 to 100. We can name its as S1.

Then, you use trapz to calcutate integral of "blue" line with dB from 60 to 75. We can name it as S2.

Next, you use trapz to compute integral of "red" line with dB from 75 to 100. We can name it as S3.

Finally, you compute S = S1 - S2 - S3.

Hope this would help you.

[Priscilla Schmitz]

I like your idea and appreciate your help but i have 378 different plots that i will need to do the same calculation and the intersection between these curves vary accordingly to the each of 378 plots. It is tricky

[infinity]

Hello,

My suggestion just applicable for the given figure.

However, you can do it in more general by using "polyarea". You can find how to use it in this link

https://it.mathworks.com/help/matlab/ref/polyarea.html

Now, what we can do is to find polygrons and use some conditions to know which one we should be added and which one should be eleminated.

[Priscilla Schmitz]

good, how do i find the intersection points between two curves?

[Star Strider]

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