[R] problems with max.col()

[Martin Maechler]

The only problem is that in your R installation

  ?max.col

does (as you say) not give you the help information.
==> problem with your installation only

Because help pages says

>> Details:
>> 
>>      Ties are broken at random.  The determination of ``tie'' assumes
>>      that the entries are probabilities: there is a relative tolerance
>>      of 1e-5, relative to the largest entry in the row.

and you *do* have ties, hence the result is random.

Regards,
Martin Maechler <maechler at stat.math.ethz.ch>	http://stat.ethz.ch/~maechler/
Seminar fuer Statistik, ETH-Zentrum  LEO C16	Leonhardstr. 27
ETH (Federal Inst. Technology)	8092 Zurich	SWITZERLAND
phone: x-41-1-632-3408		fax: ...-1228			<><



>>>>> "heberto" == heberto ghezzo <g.heberto at lycos.com>
>>>>>     on Thu, 24 Apr 2003 12:07:22 -0400 writes:

    heberto> Hello, I think the following qualify as a bug
    heberto> given:
    heberto> x<-c(1,2,3,4,2,4,2,2,4,2,2,2,4,3,2,1)
    heberto> z<-embed(x,4)
    heberto> z
    heberto> [,1] [,2] [,3] [,4]
    heberto> [1,]    4    3    2    1
    heberto> [2,]    2    4    3    2
    heberto> [3,]    4    2    4    3
    heberto> [4,]    2    4    2    4
    heberto> [5,]    2    2    4    2
    heberto> [6,]    4    2    2    4
    heberto> [7,]    2    4    2    2
    heberto> [8,]    2    2    4    2
    heberto> [9,]    2    2    2    4
    heberto> [10,]    4    2    2    2
    heberto> [11,]    3    4    2    2
    heberto> [12,]    2    3    4    2
    heberto> [13,]    1    2    3    4
    >> 
    heberto> max.col(z)
    heberto> [1] 1 2 3 4 3 1 2 3 4 1 2 3 4
    heberto> Why?     ^ ^
    >> 1 2
    heberto> or should be
    heberto> [1] 1 2 3 4 3 4 2 3 4 1 2 3 4
    heberto> i.e. the first column with the max, or the last column
    heberto> same if
    heberto> z <- embed(x,5)
    heberto> max.col(z)
    heberto> [1] 2 1 2 5 1 5 3 4 1 2 3 4
    heberto> where it should be either of:
    heberto> 2 1 2 3 1 2 3 4 1 2 3 4
    heberto> 2 3 4 5 4 5 3 4 5 2 3 4
    heberto> or I am missing something?
    heberto> ?max.col does not return anything
    heberto> R 1.7.0 on Win98
    heberto> .
    heberto> Heberto.Ghezzo at McGill.ca

    heberto> ______________________________________________
    heberto> R-help at stat.math.ethz.ch mailing list
    heberto> https://www.stat.math.ethz.ch/mailman/listinfo/r-help