On May 4, 2012, at 3:00 PM, Diego Rojas wrote:
Thanks, I know about it but i wat to find several local maxima, so
in other words I need a way to identify the places in the surface
where both slopes are equal to 0 and the second derivative is
negative.
There is no way that I know that will produce a mathematical function
that would support symbolic manipulations of that sort for the results
obtainable from a loess-object. I was expecting that you would be
approaching this numerically and doing evaluations on a grid. Testing
for equality to 0 is not a good practice if following that route. Sign
reversal would be a more sensible criterion. ( And you _would_ be
using predict.loess(). )
Still no data example or code offered, so not pursuing further efforts
at illustration.
On Fri, May 4, 2012 at 9:28 AM, David Winsemius <dwinsem...@comcast.net
> wrote:
On May 3, 2012, at 6:09 PM, Diego Rojas wrote:
If a run a LOESS model and then produce a smoothed surface: Is there
any
way to determine the coordinates of the local maxima on the surface?
?predict # it has a loess method.
[[alternative HTML version deleted]]
David Winsemius, MD
West Hartford, CT
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