And, oddly enough :-), integrate.xy does pretty much exactly what I
suggested. Thanks for providing that reference
I would be interested in seeing how the original poster's data works
out using integrate.xy as opposed to simply calculating x*y
By the way, since the original data were 'percent of total volume' over
each hour of the day, how could the integral NOT be 100%?
Carl
Gabor Grothendieck wrote:
There is an integrate.xy in sfsmic. Limitations discussed there.
On Tue, Jul 1, 2008 at 6:27 PM, stephen sefick <[EMAIL PROTECTED]> wrote:
I would like to know the answer to this question now that I know what we are
getting at. integrate() looks like it is the right thing, but it has to use
a function- I would like to know how to just integrate the area under a
curve with just an input of x and y coordinates.
Stephen
On Tue, Jul 1, 2008 at 5:22 PM, Carl Witthoft <[EMAIL PROTECTED]> wrote:
I think the previous answer (to use lm() ) is not necessarily the best
option.
Since what you want is the definite integral (area under the curve), you
can just use one of the existing definite integration tools (sorry, I don't
recall the names because I don't use them).
If you want to get a "smoothed" curve to remove errors in your data points,
I'd recommend fitting a spline and integrating under that.
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