Josep Maria Campanera Alsina
2008-Feb-21 10:56 UTC
[R] Finding local maxima (height) in a matrix data (6 spatial coordinates)?
Dear all, I wonder which R algorithm could perform a search of local maxima in an spatial grid, in other words, having the coordinates of a map (x,y,z... up to 6 coordinates) and then the altitude/height at each point (h) (in total 7 numerical variables) I would like to localise the peaks (local maxima) of that topological surface. Which R algorithm can perform this? Thanks a lot, Josep Maria,
Ben Bolker
2008-Feb-21 13:59 UTC
[R] Finding local maxima (height) in a matrix data (6 spatial coordinates)?
Josep Maria Campanera Alsina <campanera <at> ub.edu> writes:> > Dear all, > I wonder which R algorithm could perform a search of local maxima in > an spatial grid, in other words, having the coordinates of a map > (x,y,z... up to 6 coordinates) and then the altitude/height at each > point (h) (in total 7 numerical variables) I would like to localise > the peaks (local maxima) of that topological surface. Which R > algorithm can perform this? >optim finds local minima. The quick and dirty way to do this would be to start optim at many randomly chosen starting points within your space, and keep a list of the optima you found. Try googling "tabu search continuous" if you're interesting in some fancier approaches (don't think any of these are implemented in R, though). good luck Ben Bolker