Re: [R] First and second derivatives of raw observations

2010-08-30 Thread Spencer Graves
p.s. My suggestion is a special case of Duncan Murdoch's suggestion: If you have a model that should fit the data, use it. If you don't -- or if you have only something rather general -- then the more general tools of functional data analysis may be useful. ## Ther

Re: [R] First and second derivatives of raw observations

2010-08-30 Thread Spencer Graves
There is a strong argument for fitting something like splines and then differentiating the spline fit. I trust you won't object to my immodest recommendation of the "fda" package and book by Ramsay, Hooker and Graves (2009) Functional Data Analysis with R and Matlab (Springer).

Re: [R] First and second derivatives of raw observations

2010-08-30 Thread Duncan Murdoch
On 30/08/2010 6:40 PM, mtor...@math.carleton.ca wrote: Dear all, I was asked to send the following question: We have some (raw) observations and would like to get the first and second derivatives in R. Any comment would be appreciated. Fit a model, and take derivatives of the fit. Which mode

Re: [R] First and second derivatives of raw observations

2010-08-30 Thread David Winsemius
On Aug 30, 2010, at 6:40 PM, mtor...@math.carleton.ca wrote: Dear all, I was asked to send the following question: We have some (raw) observations and would like to get the first and second derivatives in R. Any comment would be appreciated. From the time of Newton, the quick and dirty (

Re: [R] First and second derivatives of raw observations

2010-08-30 Thread mtorabi
Dear all, I was asked to send the following question: We have some (raw) observations and would like to get the first and second derivatives in R. Any comment would be appreciated. Thanks, Mahmoud __ R-help@r-project.org mailing list https://stat.ethz