Re: [R] find inflexion point of discrete value list with R

>>> d2y <- diff(dy) >>> which(dy==0) ## critical values >>> sign(s2y)[which(dy==0)] ## test for max/min/saddle >>> which(d2y==0) ## inflection points >> >> I would think that testing for d2y==0 would be akin to the error in >> numeric analysis warned about in FAQ 7.31. Seems unlikely that

Re: [R] find inflexion point of discrete value list with R

On 12-01-02 04:09 PM, David Winsemius wrote: > > On Jan 2, 2012, at 11:49 AM, Ben Bolker wrote: > >> Jonas Stein jonasstein.de> writes: >> >>> >>> i have a list of values like this >>> >>> x y >>> 1 3 >>> 2 2 >> >> [snip] >> >>> >>> and need the inflexion [sic] points (and all max and min). >>>

Re: [R] find inflexion point of discrete value list with R

On Jan 2, 2012, at 11:49 AM, Ben Bolker wrote: Jonas Stein jonasstein.de> writes: i have a list of values like this x y 1 3 2 2 [snip] and need the inflexion [sic] points (and all max and min). Is there a nice way to get the local max, min and inflexion points? diff(y) gives you t

Re: [R] find inflexion point of discrete value list with R

Ben Bolker gmail.com> writes: > > Jonas Stein jonasstein.de> writes: > [snip] > [snip] > sign(s2y)[which(dy==0)] ## test for max/min/saddle oops, obviously this should be sign(d2y)[which(dy==0)] __ R-help@r-project.org mailing list https

Re: [R] find inflexion point of discrete value list with R

Jonas Stein jonasstein.de> writes: > > i have a list of values like this > > x y > 1 3 > 2 2 [snip] > > and need the inflexion points (and all max and min). > Is there a nice way to get the local max, min and inflexion points? diff(y) gives you the first difference, the analogue of the

[R] find inflexion point of discrete value list with R

i have a list of values like this x y 1 3 2 2 3 3 4 4 5 5 6 4 7 3 8 2 9 3 and need the inflexion points (and all max and min). Is there a nice way to get the local max, min and inflexion points? kind regards, -- Jonas Stein __ R-help@r-project.org