[R] gradient
David Winsemius
dwinsemius at comcast.net
Sat Mar 31 23:54:36 CEST 2012
On Mar 31, 2012, at 3:58 PM, mariam behboudi wrote:
> Hello
> In matlab we have " gradient(F,h) " where h is a scalar uses h
> as the
> spacing between points in each direction. Now I need to use this
> function
> in R. and I dont know how can I should define my function that I
> haave "h"
> in R?
I'm not a matlab user, but perhaps if you define 'F' to be an n-
column matrix and require 'h' to be of length one:
gradient <- function(F,h) { if( !is.matrix(F) | length(h) == 0 )
{ stop() }
return( apply(F ,2, diff)/h) }
(The grad function in numDeriv takes a function as its first argument
which is not what I thought you were asking for.)
--
David Winsemius, MD
West Hartford, CT
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