From Gregor.Gorjanc at bfro.uni-lj.si  Thu Aug  7 12:21:45 2008
From: Gregor.Gorjanc at bfro.uni-lj.si (Gregor.Gorjanc at bfro.uni-lj.si)
Date: Thu,  7 Aug 2008 12:21:45 +0200 (CEST)
Subject: [Rd] Methods for format() are not consistent with NA values
	(PR#12385)
Message-ID: <20080807102145.E44EB282EFC1@mail.pubhealth.ku.dk>

Hi!

Methods for format() are not consistent when applied to vectors
having NA values. Some methods encode NA values to "NA"
by default, while other do not. It would be much more easier to
write other functions if these functions would all behave
consistently.

Examples produced with R

> version
               _
platform       i486-pc-linux-gnu
arch           i486
os             linux-gnu
system         i486, linux-gnu
status
major          2
minor          7.1
year           2008
month          06
day            23
svn rev        45970
language       R
version.string R version 2.7.1 (2008-06-23)

testData <- data.frame(
                       fac1=3Dfactor(c(NA, letters[1:9], "hjh")),
                       fac2=3Dfactor(c(letters[6:15], NA)),
                       cha1=3Dc(letters[17:26], NA),
                       cha2=3Dc(NA, "longer", letters[25:17]),
                       stringsAsFactors=3DFALSE)
levels(testData$fac1) <- c(levels(testData$fac1), "unusedLevel")
testData$Date <- as.Date("1900-1-1")
testData$Date[2] <- NA
testData$POSIXt <- as.POSIXct(strptime("1900-1-1 01:01:01",
                                       format=3D"%Y-%m-%d %H:%M:%S"))
testData$POSIXt[5] <- NA

## --- Character ---

> format(testData$cha1)
 [1] "q " "r " "s " "t " "u " "v " "w " "x " "y " "z " "NA"

> format(testData$cha1, na.encode=3DTRUE)
 [1] "q " "r " "s " "t " "u " "v " "w " "x " "y " "z " "NA"

> format(testData$cha1, na.encode=3DFALSE)
 [1] "q" "r" "s" "t" "u" "v" "w" "x" "y" "z" NA

## --- Factor ---

> format(testData$fac1)
 [1] "NA " "a  " "b  " "c  " "d  " "e  " "f  " "g  " "h  " "i  " "hjh"

> format(testData$fac1, na.encode=3DTRUE)
 [1] "NA " "a  " "b  " "c  " "d  " "e  " "f  " "g  " "h  " "i  " "hjh"

> format(testData$fac1, na.encode=3DFALSE)
 [1] NA    "a  " "b  " "c  " "d  " "e  " "f  " "g  " "h  " "i  " "hjh"

## --- Numeric et al. ---

## na.encode has no effect

## --- Date ---

> format(testData$Date)
 [1] "1900-01-01" NA           "1900-01-01" "1900-01-01" "1900-01-01"
 [6] "1900-01-01" "1900-01-01" "1900-01-01" "1900-01-01" "1900-01-01"
[11] "1900-01-01"

> format(testData$Date, na.encode=3DTRUE)
 [1] "1900-01-01" NA           "1900-01-01" "1900-01-01" "1900-01-01"
 [6] "1900-01-01" "1900-01-01" "1900-01-01" "1900-01-01" "1900-01-01"
[11] "1900-01-01"

> format(testData$Date, na.encode=3DFALSE)
 [1] "1900-01-01" NA           "1900-01-01" "1900-01-01" "1900-01-01"
 [6] "1900-01-01" "1900-01-01" "1900-01-01" "1900-01-01" "1900-01-01"
[11] "1900-01-01"

## --- POSIXt ---

> format(testData$POSIXt)
 [1] "1900-01-01 01:01:01" "1900-01-01 01:01:01" "1900-01-01 01:01:01"
 [4] "1900-01-01 01:01:01" NA                    "1900-01-01 01:01:01"
 [7] "1900-01-01 01:01:01" "1900-01-01 01:01:01" "1900-01-01 01:01:01"
[10] "1900-01-01 01:01:01" "1900-01-01 01:01:01"

> format(testData$POSIXt, na.encode=3DTRUE)
 [1] "1900-01-01 01:01:01" "1900-01-01 01:01:01" "1900-01-01 01:01:01"
 [4] "1900-01-01 01:01:01" NA                    "1900-01-01 01:01:01"
 [7] "1900-01-01 01:01:01" "1900-01-01 01:01:01" "1900-01-01 01:01:01"
[10] "1900-01-01 01:01:01" "1900-01-01 01:01:01"

> format(testData$POSIXt, na.encode=3DFALSE)
 [1] "1900-01-01 01:01:01" "1900-01-01 01:01:01" "1900-01-01 01:01:01"
 [4] "1900-01-01 01:01:01" NA                    "1900-01-01 01:01:01"
 [7] "1900-01-01 01:01:01" "1900-01-01 01:01:01" "1900-01-01 01:01:01"
[10] "1900-01-01 01:01:01" "1900-01-01 01:01:01"

--
Lep pozdrav / With regards,
    Gregor Gorjanc
----------------------------------------------------------------------
University of Ljubljana     PhD student
Biotechnical Faculty        www: http://gregor.gorjanc.googlepages.com
Zootechnical Department     blog: http://ggorjan.blogspot.com
Groblje 3                   mail: gregor.gorjanc <at> bfro.uni-lj.si
SI-1230 Domzale             fax: +386 (0)1 72 17 888
Slovenia, Europe            tel: +386 (0)1 72 17 861



[Rd] Methods for format() are not consistent with NA values (PR#12385)
Gregor.Gorjanc at bfro.uni-lj.si