Message-ID: <3EA8128C.60301@statistik.uni-dortmund.de>
Date: 2003-04-24T16:36:28Z
From: Uwe Ligges
Subject: problems with max.col()
In-Reply-To: <PKAHOFDKPLJALEAA@mailcity.com>
heberto ghezzo wrote:
> Hello, I think the following qualify as a bug
> given:
> x<-c(1,2,3,4,2,4,2,2,4,2,2,2,4,3,2,1)
> z<-embed(x,4)
> z
> [,1] [,2] [,3] [,4]
> [1,] 4 3 2 1
> [2,] 2 4 3 2
> [3,] 4 2 4 3
> [4,] 2 4 2 4
> [5,] 2 2 4 2
> [6,] 4 2 2 4
> [7,] 2 4 2 2
> [8,] 2 2 4 2
> [9,] 2 2 2 4
> [10,] 4 2 2 2
> [11,] 3 4 2 2
> [12,] 2 3 4 2
> [13,] 1 2 3 4
>
> max.col(z)
> [1] 1 2 3 4 3 1 2 3 4 1 2 3 4
> Why? ^ ^
>
>> 1 2
>
> or should be
> [1] 1 2 3 4 3 4 2 3 4 1 2 3 4
> i.e. the first column with the max, or the last column
> same if
> z <- embed(x,5)
> max.col(z)
> [1] 2 1 2 5 1 5 3 4 1 2 3 4
> where it should be either of:
> 2 1 2 3 1 2 3 4 1 2 3 4
> 2 3 4 5 4 5 3 4 5 2 3 4
> or I am missing something?
Reading the word "random" in its help file:
"Find the maximum position for each row of a matrix, breaking ties at
random."
You observed another bug: The Compiled HTML help file (on Windows)
doesn't come up with ?max.col. Nevertheless, brosing through the index
results in a working link (and a page).
I'm not sure whether the bug is in R or in Microsoft's help compiler ...
I will take a look later (and move the thread to R-devel in case of
further investigations).
Uwe Ligges
> ?max.col does not return anything
> R 1.7.0 on Win98
> .
> Heberto.Ghezzo at McGill.ca
>
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