Compute an integral from data points

[jcmbl]

Hi guys,

I have 2 weird sets of points to define 2 curves. I need to compute the area between these two. Is there any straightforward way to do it? The position of the curves is changing with respect to X axis, so I'd need a general methodology to do my task, not just for a specific set of points.
I'd appreciate any help.

Cheers

 

[IRstuff]

Why not take the difference of the two numerical integrals?

Assuming, of course, you know what the interval is to start with.

TTFN

 

[GregLocock]

"Why not take the difference of the two numerical integrals?"

Or why not take the integral of the differences between the two curves?



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[IRstuff]

I assumed that the points on the two curves might not line up. If they dno't line up, you'd have to do interpolation first.

If you run the numerical integrals separately, you can do that in Excel.

TTFN

 

[GregLocock]

I was just being silly (mostly)

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[jcmbl]

sorry guys for the stupid question. I did some drawings to help me understand the area I needed, but it was proved I was doing something silly (I was getting some open segments of the curves which I couldnt compute). Of course the area is the difference between the 2 curves, although I'm not newbie at all to integrals, but it just slipped.

Cheers