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Petr Pikal

2006-Aug-10 14:32 UTC

[R] bug in interaction order when using drop?

Hallo all
> version               _                                     
platform       i386-pc-mingw32                       
arch           i386                                  
os             mingw32                               
system         i386, mingw32                         
status         beta                                  
major          2                                     
minor          3.1                                   
year           2006                                  
month          05                                    
day            23                                    
svn rev        38179                                 
language       R                                     
version.string Version 2.3.1 beta (2006-05-23 r38179)>
When I use interaction(....) without drop=T parameters I will get 
neatly organized factor with "protiproud" and "souproud"
aligned.
> levels(interaction(vykon, teplota, proudeni)) [1] "3.750.protiproud"  "12.750.protiproud"
"3.775.protiproud"
"12.775.protiproud" "3.800.protiproud" 
"12.800.protiproud"
 [7] "3.825.protiproud"  "12.825.protiproud"
"3.850.protiproud"
"12.850.protiproud" "3.750.souproud"   
"12.750.souproud"
[13] "3.775.souproud"    "12.775.souproud"  
"3.800.souproud"
"12.800.souproud"   "3.825.souproud"   
"12.825.souproud"
[19] "3.850.souproud"    "12.850.souproud"  

However when I use 
> levels(interaction(vykon, teplota, proudeni, drop=T))[1] "3.775.protiproud"  "3.800.souproud"   
"3.750.souproud"
"12.850.souproud"   "12.825.protiproud"

everything is out of order. I know I can reorder any factor according 
to my wish but it would be good to have it ordered same way as 
without using drop.

Everything comes from unique in

if (drop) {
        f <- unique(ans[!is.na(ans)])
        ans <- match(ans, f)
        lvs <- lvs[f]
}

maybe it can be modified.

if (drop) {
        f <- unique(ans[!is.na(ans)])
        ord <- order(f)
        ans <- match(ans, f)
        lvs <- lvs[f[ord]]
        }

which seems to work but I am not sure if it does not makes problems 
having NA in data.

Here is my data frame.
Thank you 

Petr Pikal
> dump("df", file=stdout()) df <-
structure(list(proudeni = structure(as.integer(c(1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 
1, 1, 1)), .Label = c("protiproud", "souproud"), class =
"factor"),
    vykon = as.integer(c(3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
    3, 3, 3, 3, 3, 3, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 
    12, 12, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
    3, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 3, 3, 
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 12, 12, 12, 
    12, 12, 12, 12, 12, 12, 12, 12, 12, 3, 3, 3, 3, 3, 3, 3, 
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 12, 12, 12, 12, 12, 12, 
    12, 12, 12, 12, 12, 12)), teplota = as.integer(c(775, 775, 
    775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 
    775, 775, 775, 775, 800, 800, 800, 800, 800, 800, 800, 800, 
    800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 750, 850, 
    850, 850, 850, 850, 850, 825, 825, 825, 825, 825, 825, 775, 
    775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 
    775, 775, 775, 775, 775, 800, 800, 800, 800, 800, 800, 800, 
    800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 750, 
    850, 850, 850, 850, 850, 850, 825, 825, 825, 825, 825, 825, 
    775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 
    775, 775, 775, 775, 775, 775, 800, 800, 800, 800, 800, 800, 
    800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 
    750, 850, 850, 850, 850, 850, 850, 825, 825, 825, 825, 825, 
    825, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 
    775, 775, 775, 775, 775, 775, 775, 800, 800, 800, 800, 800, 
    800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 
    800, 750, 850, 850, 850, 850, 850, 850, 825, 825, 825, 825, 
    825, 825))), .Names = c("proudeni", "vykon",
"teplota"),
row.names = c("1", 
"2", "3", "4", "5", "6",
"7", "8", "9", "10", "11",
"12", "13",
"14", "15", "16", "17", "18",
"19", "20", "21", "22", "23",
"24",
"25", "26", "27", "28", "29",
"30", "31", "32", "33", "34",
"35",
"36", "37", "38", "39", "40",
"41", "42", "43", "44", "45",
"46",
"47", "48", "49", "50", "51",
"52", "53", "54", "55", "56",
"57",
"58", "59", "60", "61", "62",
"63", "64", "65", "66", "67",
"68",
"69", "70", "71", "72", "73",
"74", "75", "76", "77", "78",
"79",
"80", "81", "82", "83", "84",
"85", "86", "87", "88", "89",
"90",
"91", "92", "93", "94", "95",
"96", "97", "98", "99", "100",
"101", "102", "103", "104",
"105", "106", "107", "108",
"109",
"110", "111", "112", "113",
"114", "115", "116", "117",
"118",
"119", "120", "121", "122",
"123", "124", "125", "126",
"127",
"128", "129", "130", "131",
"132", "133", "134", "135",
"136",
"137", "138", "139", "140",
"141", "142", "143", "144",
"145",
"146", "147", "148", "149",
"150", "151", "152", "153",
"154",
"155", "156", "157", "158",
"159", "160", "161", "162",
"163",
"164", "165", "166", "167",
"168", "169", "170", "171",
"172",
"173", "174", "175", "176",
"177", "178", "179", "180",
"181",
"182", "183", "184", "185",
"186", "187", "188", "189",
"190",
"191", "192", "193", "194",
"195", "196"), class =
"data.frame")> Petr Pikalpetr.pikal at precheza.cz

Petr Pikal

2006-Aug-10 15:12 UTC

head link

[R] bug in interaction order when using drop?

Ooops, my first suggestion reorders factor itself but

if (drop) factor(ans) else ans

instead of whole drop construction shall preserve levels order 
without changing order of factor

Petr

On 10 Aug 2006 at 16:32, Petr Pikal wrote:

From:           	"Petr Pikal" <petr.pikal at precheza.cz>
To:             	r-help at stat.math.ethz.ch
Date sent:      	Thu, 10 Aug 2006 16:32:54 +0200
Priority:       	normal
Subject:        	[R] bug in interaction order when using drop?
> Hallo all
> 
> > version
>                _                                   
> platform       i386-pc-mingw32                       
> arch           i386                                  
> os             mingw32                               
> system         i386, mingw32                         
> status         beta                                  
> major          2                                   
> minor          3.1                                   
> year           2006                                  
> month          05                                   
> day            23                                   
> svn rev        38179                                 
> language       R                                   
> version.string Version 2.3.1 beta (2006-05-23 r38179)
> >
> 
> When I use interaction(....) without drop=T parameters I will get
> neatly organized factor with "protiproud" and
"souproud" aligned.
> 
> > levels(interaction(vykon, teplota, proudeni))
>  [1] "3.750.protiproud"  "12.750.protiproud"
"3.775.protiproud"
> "12.775.protiproud" "3.800.protiproud" 
"12.800.protiproud"
>  [7] "3.825.protiproud"  "12.825.protiproud"
"3.850.protiproud"
> "12.850.protiproud" "3.750.souproud"   
"12.750.souproud"  [13]
> "3.775.souproud"    "12.775.souproud"  
"3.800.souproud"
> "12.800.souproud"   "3.825.souproud"   
"12.825.souproud"  [19]
> "3.850.souproud"    "12.850.souproud"  
> 
> However when I use 
> 
> > levels(interaction(vykon, teplota, proudeni, drop=T))
> [1] "3.775.protiproud"  "3.800.souproud"   
"3.750.souproud"
> "12.850.souproud"   "12.825.protiproud"
> 
> everything is out of order. I know I can reorder any factor according
> to my wish but it would be good to have it ordered same way as without
> using drop.
> 
> Everything comes from unique in
> 
> if (drop) {
>         f <- unique(ans[!is.na(ans)])
>         ans <- match(ans, f)
>         lvs <- lvs[f]
> }
> 
> maybe it can be modified.
> 
> if (drop) {
>         f <- unique(ans[!is.na(ans)])
>         ord <- order(f)
>         ans <- match(ans, f)
>         lvs <- lvs[f[ord]]
>         }
> 
> which seems to work but I am not sure if it does not makes problems
> having NA in data.
> 
> Here is my data frame.
> Thank you 
> 
> Petr Pikal
> 
> > dump("df", file=stdout()) 
> df <-
> structure(list(proudeni = structure(as.integer(c(1, 1, 1, 1, 
> 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 
> 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 
> 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
> 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
> 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
> 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
> 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
> 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 
> 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 
> 1, 1, 1)), .Label = c("protiproud", "souproud"), class
= "factor"),
>     vykon = as.integer(c(3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
>     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
>     3, 3, 3, 3, 3, 3, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 
>     12, 12, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
>     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
>     3, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 3, 3, 
>     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
>     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 12, 12, 12, 
>     12, 12, 12, 12, 12, 12, 12, 12, 12, 3, 3, 3, 3, 3, 3, 3, 
>     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
>     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 12, 12, 12, 12, 12, 12, 
>     12, 12, 12, 12, 12, 12)), teplota = as.integer(c(775, 775, 
>     775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 
>     775, 775, 775, 775, 800, 800, 800, 800, 800, 800, 800, 800, 
>     800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 750, 850, 
>     850, 850, 850, 850, 850, 825, 825, 825, 825, 825, 825, 775, 
>     775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 
>     775, 775, 775, 775, 775, 800, 800, 800, 800, 800, 800, 800, 
>     800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 750, 
>     850, 850, 850, 850, 850, 850, 825, 825, 825, 825, 825, 825, 
>     775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 
>     775, 775, 775, 775, 775, 775, 800, 800, 800, 800, 800, 800, 
>     800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 
>     750, 850, 850, 850, 850, 850, 850, 825, 825, 825, 825, 825, 
>     825, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 
>     775, 775, 775, 775, 775, 775, 775, 800, 800, 800, 800, 800, 
>     800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 
>     800, 750, 850, 850, 850, 850, 850, 850, 825, 825, 825, 825, 
>     825, 825))), .Names = c("proudeni", "vykon",
"teplota"),
> row.names = c("1", 
> "2", "3", "4", "5", "6",
"7", "8", "9", "10", "11",
"12", "13",
> "14", "15", "16", "17",
"18", "19", "20", "21", "22",
"23", "24",
> "25", "26", "27", "28",
"29", "30", "31", "32", "33",
"34", "35",
> "36", "37", "38", "39",
"40", "41", "42", "43", "44",
"45", "46",
> "47", "48", "49", "50",
"51", "52", "53", "54", "55",
"56", "57",
> "58", "59", "60", "61",
"62", "63", "64", "65", "66",
"67", "68",
> "69", "70", "71", "72",
"73", "74", "75", "76", "77",
"78", "79",
> "80", "81", "82", "83",
"84", "85", "86", "87", "88",
"89", "90",
> "91", "92", "93", "94",
"95", "96", "97", "98", "99",
"100", "101",
> "102", "103", "104", "105",
"106", "107", "108", "109",
"110", "111",
> "112", "113", "114", "115",
"116", "117", "118", "119",
"120", "121",
> "122", "123", "124", "125",
"126", "127", "128", "129",
"130", "131",
> "132", "133", "134", "135",
"136", "137", "138", "139",
"140", "141",
> "142", "143", "144", "145",
"146", "147", "148", "149",
"150", "151",
> "152", "153", "154", "155",
"156", "157", "158", "159",
"160", "161",
> "162", "163", "164", "165",
"166", "167", "168", "169",
"170", "171",
> "172", "173", "174", "175",
"176", "177", "178", "179",
"180", "181",
> "182", "183", "184", "185",
"186", "187", "188", "189",
"190", "191",
> "192", "193", "194", "195",
"196"), class = "data.frame") > Petr Pikal
> petr.pikal at precheza.cz
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html and provide commented,
> minimal, self-contained, reproducible code.
Petr Pikal
petr.pikal at precheza.cz

Prof Brian Ripley

2006-Aug-11 11:31 UTC

head link

[R] bug in interaction order when using drop?

On Thu, 10 Aug 2006, Petr Pikal wrote:
> Ooops, my first suggestion reorders factor itself but
> 
> if (drop) factor(ans) else ans
> 
> instead of whole drop construction shall preserve levels order 
> without changing order of factor
Even easier would be to return ans[,drop=drop].  It seems to me that there 
is an argument for expecting interaction(..., drop=TRUE) to give the same 
result as interaction(...)[,drop=TRUE], but little argument that any 
ordering is a *bug*.

The order of the levels of a factor are arbitrary, and in fact they seem 
to me to be in a strange order, with the levels of the first factor 
varying fastest (reverse lexiographic order).
> levels(interaction(c("A", "A", "B"),
letters[1:3]))[1] "A.a" "B.a" "A.b" "B.b"
"A.c" "B.c"

so the existing
> levels(interaction(c("A", "A", "B"),
letters[1:3], drop=T))[1] "A.a" "A.b" "B.c"

looks more sensible in this case.
> 
> Petr
> 
> On 10 Aug 2006 at 16:32, Petr Pikal wrote:
> 
> From:           	"Petr Pikal" <petr.pikal at precheza.cz>
> To:             	r-help at stat.math.ethz.ch
> Date sent:      	Thu, 10 Aug 2006 16:32:54 +0200
> Priority:       	normal
> Subject:        	[R] bug in interaction order when using drop?
> 
> > Hallo all
> > 
> > > version
> >                _                                   
> > platform       i386-pc-mingw32                       
> > arch           i386                                  
> > os             mingw32                               
> > system         i386, mingw32                         
> > status         beta                                  
> > major          2                                   
> > minor          3.1                                   
> > year           2006                                  
> > month          05                                   
> > day            23                                   
> > svn rev        38179                                 
> > language       R                                   
> > version.string Version 2.3.1 beta (2006-05-23 r38179)
> > >
> > 
> > When I use interaction(....) without drop=T parameters I will get
> > neatly organized factor with "protiproud" and
"souproud" aligned.
> > 
> > > levels(interaction(vykon, teplota, proudeni))
> >  [1] "3.750.protiproud"  "12.750.protiproud"
"3.775.protiproud"
> > "12.775.protiproud" "3.800.protiproud" 
"12.800.protiproud"
> >  [7] "3.825.protiproud"  "12.825.protiproud"
"3.850.protiproud"
> > "12.850.protiproud" "3.750.souproud"   
"12.750.souproud"  [13]
> > "3.775.souproud"    "12.775.souproud"  
"3.800.souproud"
> > "12.800.souproud"   "3.825.souproud"   
"12.825.souproud"  [19]
> > "3.850.souproud"    "12.850.souproud"  
> > 
> > However when I use 
> > 
> > > levels(interaction(vykon, teplota, proudeni, drop=T))
> > [1] "3.775.protiproud"  "3.800.souproud"   
"3.750.souproud"
> > "12.850.souproud"   "12.825.protiproud"
> > 
> > everything is out of order. I know I can reorder any factor according
> > to my wish but it would be good to have it ordered same way as without
> > using drop.
> > 
> > Everything comes from unique in
> > 
> > if (drop) {
> >         f <- unique(ans[!is.na(ans)])
> >         ans <- match(ans, f)
> >         lvs <- lvs[f]
> > }
> > 
> > maybe it can be modified.
> > 
> > if (drop) {
> >         f <- unique(ans[!is.na(ans)])
> >         ord <- order(f)
> >         ans <- match(ans, f)
> >         lvs <- lvs[f[ord]]
> >         }
> > 
> > which seems to work but I am not sure if it does not makes problems
> > having NA in data.
> > 
> > Here is my data frame.
> > Thank you 
> > 
> > Petr Pikal
> > 
> > > dump("df", file=stdout()) 
> > df <-
> > structure(list(proudeni = structure(as.integer(c(1, 1, 1, 1, 
> > 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 
> > 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 
> > 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
> > 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
> > 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
> > 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
> > 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
> > 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 
> > 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 
> > 1, 1, 1)), .Label = c("protiproud", "souproud"),
class = "factor"),
> >     vykon = as.integer(c(3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
> >     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
> >     3, 3, 3, 3, 3, 3, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 
> >     12, 12, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
> >     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
> >     3, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 3, 3, 
> >     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
> >     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 12, 12, 12, 
> >     12, 12, 12, 12, 12, 12, 12, 12, 12, 3, 3, 3, 3, 3, 3, 3, 
> >     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
> >     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 12, 12, 12, 12, 12, 12, 
> >     12, 12, 12, 12, 12, 12)), teplota = as.integer(c(775, 775, 
> >     775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 
> >     775, 775, 775, 775, 800, 800, 800, 800, 800, 800, 800, 800, 
> >     800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 750, 850, 
> >     850, 850, 850, 850, 850, 825, 825, 825, 825, 825, 825, 775, 
> >     775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 
> >     775, 775, 775, 775, 775, 800, 800, 800, 800, 800, 800, 800, 
> >     800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 750, 
> >     850, 850, 850, 850, 850, 850, 825, 825, 825, 825, 825, 825, 
> >     775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 
> >     775, 775, 775, 775, 775, 775, 800, 800, 800, 800, 800, 800, 
> >     800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 
> >     750, 850, 850, 850, 850, 850, 850, 825, 825, 825, 825, 825, 
> >     825, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 775, 
> >     775, 775, 775, 775, 775, 775, 775, 800, 800, 800, 800, 800, 
> >     800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 800, 
> >     800, 750, 850, 850, 850, 850, 850, 850, 825, 825, 825, 825, 
> >     825, 825))), .Names = c("proudeni", "vykon",
"teplota"),
> > row.names = c("1", 
> > "2", "3", "4", "5",
"6", "7", "8", "9", "10",
"11", "12", "13",
> > "14", "15", "16", "17",
"18", "19", "20", "21", "22",
"23", "24",
> > "25", "26", "27", "28",
"29", "30", "31", "32", "33",
"34", "35",
> > "36", "37", "38", "39",
"40", "41", "42", "43", "44",
"45", "46",
> > "47", "48", "49", "50",
"51", "52", "53", "54", "55",
"56", "57",
> > "58", "59", "60", "61",
"62", "63", "64", "65", "66",
"67", "68",
> > "69", "70", "71", "72",
"73", "74", "75", "76", "77",
"78", "79",
> > "80", "81", "82", "83",
"84", "85", "86", "87", "88",
"89", "90",
> > "91", "92", "93", "94",
"95", "96", "97", "98", "99",
"100", "101",
> > "102", "103", "104", "105",
"106", "107", "108", "109",
"110", "111",
> > "112", "113", "114", "115",
"116", "117", "118", "119",
"120", "121",
> > "122", "123", "124", "125",
"126", "127", "128", "129",
"130", "131",
> > "132", "133", "134", "135",
"136", "137", "138", "139",
"140", "141",
> > "142", "143", "144", "145",
"146", "147", "148", "149",
"150", "151",
> > "152", "153", "154", "155",
"156", "157", "158", "159",
"160", "161",
> > "162", "163", "164", "165",
"166", "167", "168", "169",
"170", "171",
> > "172", "173", "174", "175",
"176", "177", "178", "179",
"180", "181",
> > "182", "183", "184", "185",
"186", "187", "188", "189",
"190", "191",
> > "192", "193", "194", "195",
"196"), class = "data.frame") > Petr Pikal
> > petr.pikal at precheza.cz
> > 
> > ______________________________________________
> > R-help at stat.math.ethz.ch mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html and provide commented,
> > minimal, self-contained, reproducible code.
> 
> Petr Pikal
> petr.pikal at precheza.cz
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
> 
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

Petr Pikal

2006-Aug-11 12:07 UTC

head link

[R] bug in interaction order when using drop?

On 11 Aug 2006 at 12:31, Prof Brian Ripley wrote:

Date sent:      	Fri, 11 Aug 2006 12:31:55 +0100 (BST)
From:           	Prof Brian Ripley <ripley at stats.ox.ac.uk>
To:             	Petr Pikal <petr.pikal at precheza.cz>
Copies to:      	r-help at stat.math.ethz.ch
Subject:        	Re: [R] bug in interaction order when using drop?
> On Thu, 10 Aug 2006, Petr Pikal wrote:
> 
> > Ooops, my first suggestion reorders factor itself but
> > 
> > if (drop) factor(ans) else ans
> > 
> > instead of whole drop construction shall preserve levels order
> > without changing order of factor
> 
> Even easier would be to return ans[,drop=drop].  It seems to me that
> there is an argument for expecting interaction(..., drop=TRUE) to give
> the same result as interaction(...)[,drop=TRUE], but little argument
> that any ordering is a *bug*.
Maybe bug was an *exaggeration*, but what surprised me was different 
order in using interaction with and without drop. Well, I would call 
it not consistent behaviour as omitting unused levels silently change 
an order of factor levels.
> set.seed(1)
> DF<-data.frame(x=sample(LETTERS[1:3],10, replace=T), y=sample(letters[1:3],10, replace=T))
> interaction(DF$x,DF$y) [1] A.a B.a B.c C.b A.c C.b C.c B.c B.b A.c
Levels: A.a B.a C.a A.b B.b C.b A.c B.c C.c

Here is neat ordering, however as you said first level varying 
fastest.
> interaction(DF$x,DF$y, drop=T) [1] A.a B.a B.c C.b A.c C.b C.c B.c B.b A.c
Levels: A.a B.a B.c C.b A.c C.c B.b

This seems to me chaotic, but I will be glad if you explain to me 
some rational pattern in it.
> my.int(DF$x,DF$y,drop=T) # changed as suggested [1] A.a B.a B.c C.b A.c C.b C.c B.c B.b A.c
Levels: A.a B.a B.b C.b A.c B.c C.c>
Same ordering as without drop, with unused levels omitted.
Best regards.
Petr Pikal
> 
> The order of the levels of a factor are arbitrary, and in fact they
> seem to me to be in a strange order, with the levels of the first
> factor varying fastest (reverse lexiographic order).
> 
> > levels(interaction(c("A", "A", "B"),
letters[1:3]))
> [1] "A.a" "B.a" "A.b" "B.b"
"A.c" "B.c"
> 
> so the existing
> 
> > levels(interaction(c("A", "A", "B"),
letters[1:3], drop=T))
> [1] "A.a" "A.b" "B.c"
> 
> looks more sensible in this case.
> 
> > 
> > Petr
> > 
> > On 10 Aug 2006 at 16:32, Petr Pikal wrote:
> > 
> > From:           	"Petr Pikal" <petr.pikal at
precheza.cz>
> > To:             	r-help at stat.math.ethz.ch
> > Date sent:      	Thu, 10 Aug 2006 16:32:54 +0200
> > Priority:       	normal
> > Subject:        	[R] bug in interaction order when using drop?
<snip>
> > 
> > ______________________________________________
> > R-help at stat.math.ethz.ch mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html and provide commented,
> > minimal, self-contained, reproducible code.
> > 
> 
> -- 
> Brian D. Ripley,                  ripley at stats.ox.ac.uk
> Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
> University of Oxford,             Tel:  +44 1865 272861 (self) 1 South
> Parks Road,                     +44 1865 272866 (PA) Oxford OX1 3TG,
> UK                Fax:  +44 1865 272595
Petr Pikal
petr.pikal at precheza.cz

R help - Aug 2006 - bug in interaction order when using drop?

[R] bug in interaction order when using drop?

[R] bug in interaction order when using drop?

[R] bug in interaction order when using drop?

[R] bug in interaction order when using drop?