[R] Cubic B-spline, how to numerically integrate?

[Robert A LaBudde]

It's a piecewise cubic function. All you need are the knots and the 
coefficients. You can then right down the analytic formula for the integral.

It doesn't need to be numerically integrated.

At 11:57 AM 5/14/2010, David Winsemius wrote:

>On May 14, 2010, at 11:41 AM, Claudia Penaloza wrote:
>
>>(corrected version of previous posting)
>>
>>I fit a GAM to turtle growth data following methods in Limpus &
>>Chaloupka
>>1997 (http://www.int-res.com/articles/meps/149/m149p023.pdf).
>>
>>I want to obtain figures similar to Fig 3 c & f in Limpus & Chaloupka
>>(1997), which according to the figure legend are "expected size-at-age
>>functions" obtained by numerically integrating "size-specific growth
>>rate
>>functions derived using cubic B-spline fit to GAM predicted values".
>>
>>I was able to fit the cubic-B spline, but I do not know how to
>>"numerically
>>integrate" it.
>
>You need to give us the function and the appropriate limits of
>integration.
>
>>
>>Can anybody help please?
>>
>>Code and figures here:
>>https://docs.google.com/fileview?id=0B1cQ7z9xYFl2ZTZhMmMyMjAtYTA3Zi00N2QyLTkxNzMtOGYyMjdiOGU2ZWE4&hl=en
>>
>>Thank you,
>>Claudia


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Robert A. LaBudde, PhD, PAS, Dpl. ACAFS  e-mail: ral at lcfltd.com
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