Full_Name: Benny van der Vijgh Version: 2.7.2 OS: Windows Vista Submission from: (NULL) (194.171.252.108)
The return value of peaks() in package splus2R is not consistent. This is because of the call to max.col() without additional parameters which peaks() makes. max.col() has a parameter 'ties.method' which specifies how ties are handled, with "random" by default. This means that when peaks() is called on a vector with two (or more) neighbouring elements in a tie for the local maximum, these end up in the same row in the embedded matrix after which max.col() at random chooses which will be considered the maximum, thereby yielding inconsistent results, for example: > a <- c(3,5,5,3) > peaks(a) [1] FALSE FALSE FALSE FALSE > peaks(a) [1] FALSE TRUE FALSE FALSE this can be easily fixed by setting the parameter 'ties.method' for max.col() to "first" or "last", which is a matter of application and taste I think, perhaps it can even be considered to make this parameter also a parameter of peaks() and pass it to max.col() in the execution. ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel