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Alain D.

2015-Feb-26 10:08 UTC

[R] format selected columns in dataframe as character

Dear R-List,
 
#I have a df with the first two cols formatted as factor.
 
dfx <- data.frame(
group = c(rep('A', 8), rep('B', 15), rep('C', 6)),
sex = sample(c("M", "F"), size = 29, replace = TRUE),
age = runif(n = 29, min = 18, max = 54))
 
# now I want to format both factor VARs as character
# I tried
 
factor.id<-names(dfx[sapply(dfx,is.factor)])
chr.names<-which(names(dfx)%in% factor.id)
 
dfx[ , chr.names]<-as.character(dfx[ , chr.names])
# which gives me
str(dfx)
'data.frame': 29 obs. of 3 variables: $ group: chr "c(1, 1, 1, 1,
1, 1, 1, 1, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3)" "c(2, 2,
1, 1, 1,
1, 2, 1, 1, 2, 2, 1, 2, 2, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 2)"
"c(1,
1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3,
3)" "c(2, 2, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 2, 2, 2, 1, 1, 1, 1, 1, 2,
1, 1, 1,
1, 1, 2, 2, 2)" ... $ sex : chr "c(2, 2, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1,
2, 2, 2,
1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 2)" "c(1, 1, 1, 1, 1, 1, 1, 1,
2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3)" "c(2, 2, 1, 1,
1, 1, 2,
1, 1, 2, 2, 1, 2, 2, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 2)"
"c(1, 1, 1,
1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3,
3)"
... $ age : num 38.5 18 33.5 26 22.5 ...
 
#though I was hoping for something like
 
'data.frame': 29 obs. of  3 variables:
$ group: chr  "A" "A" "A" "A" ...
$ sex  : chr  "M" "F" "F" "M" ...
$ age  : num  21.3 35.2 53.8 21 23.6 ...

#What is wrong with my code?
#Thank you for any help

Best wishes 

Alain
 
 
 
	[[alternative HTML version deleted]]

JS Huang

2015-Feb-26 13:54 UTC

head link

[R] format selected columns in dataframe as character

Try as.character like the following shows.
> dfx <- data.frame( +   group = c(rep('A', 8), rep('B', 15), rep('C', 6)), 
+   sex = sample(c("M", "F"), size = 29, replace = TRUE), 
+   age = runif(n = 29, min = 18, max = 54))> dfx   group sex         age
1      A   M 41.35554346
2      A   F 47.73245469
3      A   F 42.97870796
4      A   M 52.51180396
5      A   F 46.72228944
6      A   M 48.64668630
7      A   M 36.07894452
8      A   M 26.96805121
9      B   M 30.67208692
10     B   M 45.09322672
11     B   M 31.86601692
12     B   F 53.28861780
13     B   M 27.74271305
14     B   F 52.05845066
15     B   F 18.94612430
16     B   M 48.66673378
17     B   F 53.07004762
18     B   F 48.15222416
19     B   M 32.17737802
20     B   M 37.02122907
21     B   M 39.31442046
22     B   M 27.90392578
23     B   M 44.70562356
24     C   F 53.43127126
25     C   M 49.85362283
26     C   M 40.40779822
27     C   F 31.41189728
28     C   M 47.49351314
29     C   M 46.34333618> summary(dfx) group  sex         age          
 A: 8   F:10   Min.   :18.94612  
 B:15   M:19   1st Qu.:32.17738  
 C: 6          Median :44.70562  
               Mean   :41.46947  
               3rd Qu.:48.64669  
               Max.   :53.43127  > dfx$group <- *as.character*(dfx$group)
> summary(dfx)    group           sex         age          
 Length:29          F:10   Min.   :18.94612  
 Class :character   M:19   1st Qu.:32.17738  
 Mode  :character          Median :44.70562  
                           Mean   :41.46947  
                           3rd Qu.:48.64669  
                           Max.   :53.43127  > dfx   group sex         age
1      A   M 41.35554346
2      A   F 47.73245469
3      A   F 42.97870796
4      A   M 52.51180396
5      A   F 46.72228944
6      A   M 48.64668630
7      A   M 36.07894452
8      A   M 26.96805121
9      B   M 30.67208692
10     B   M 45.09322672
11     B   M 31.86601692
12     B   F 53.28861780
13     B   M 27.74271305
14     B   F 52.05845066
15     B   F 18.94612430
16     B   M 48.66673378
17     B   F 53.07004762
18     B   F 48.15222416
19     B   M 32.17737802
20     B   M 37.02122907
21     B   M 39.31442046
22     B   M 27.90392578
23     B   M 44.70562356
24     C   F 53.43127126
25     C   M 49.85362283
26     C   M 40.40779822
27     C   F 31.41189728
28     C   M 47.49351314
29     C   M 46.34333618> dfx$sex <- *as.character*(dfx$sex)
> summary(dfx)    group               sex                 age          
 Length:29          Length:29          Min.   :18.94612  
 Class :character   Class :character   1st Qu.:32.17738  
 Mode  :character   Mode  :character   Median :44.70562  
                                       Mean   :41.46947  
                                       3rd Qu.:48.64669  
                                       Max.   :53.43127 
> class(dfx$group)
[1] "character"> dfx$group [1] "A" "A" "A" "A" "A"
"A" "A" "A" "B" "B"
"B" "B" "B" "B" "B"
"B" "B" "B"
"B" "B" "B" "B" "B"
"C"
[25] "C" "C" "C" "C"
"C"> class(dfx$sex)
[1] "character"> dfx$sex [1] "M" "F" "F" "M" "F"
"M" "M" "M" "M" "M"
"M" "F" "M" "F" "F"
"M" "F" "F"
"M" "M" "M" "M" "M"
"F"
[25] "M" "M" "F" "M"
"M"> 


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MacQueen, Don

2015-Feb-26 16:05 UTC

head link

[R] format selected columns in dataframe as character

Of course you could have created them as character vectors in the first
place:

dfx <- data.frame(
  group = c(rep('A', 8), rep('B', 15), rep('C', 6)),
  sex = sample(c("M", "F"), size = 29, replace = TRUE),
  age = runif(n = 29, min = 18, max = 54),
  stringsAsFactors=FALSE
  )


But if that is not possible in your context, then I would suggest this:

for (nm in names(dfx))
   if (is.factor(dfx[[nm]])) dfx[[nm]] <- as.character(dfx[[nm]])

It's clear and simple.



-- 
Don MacQueen

Lawrence Livermore National Laboratory
7000 East Ave., L-627
Livermore, CA 94550
925-423-1062





On 2/26/15, 2:08 AM, "Alain D." <dialvac-r at yahoo.de> wrote:
>Dear R-List,
> 
>#I have a df with the first two cols formatted as factor.
> 
>dfx <- data.frame(
>group = c(rep('A', 8), rep('B', 15), rep('C', 6)),
>sex = sample(c("M", "F"), size = 29, replace = TRUE),
>age = runif(n = 29, min = 18, max = 54))
> 
># now I want to format both factor VARs as character
># I tried
> 
>factor.id<-names(dfx[sapply(dfx,is.factor)])
>chr.names<-which(names(dfx)%in% factor.id)
> 
>dfx[ , chr.names]<-as.character(dfx[ , chr.names])
># which gives me
>str(dfx)
>'data.frame': 29 obs. of 3 variables: $ group: chr "c(1, 1, 1,
1, 1, 1,
>1, 1, 2,
>2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3)" "c(2,
2, 1,
>1, 1,
>1, 2, 1, 1, 2, 2, 1, 2, 2, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2,
2)"
>"c(1,
>1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3,
>3, 3, 3,
>3)" "c(2, 2, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 2, 2, 2, 1, 1, 1, 1, 1,
2, 1,
>1, 1,
>1, 1, 2, 2, 2)" ... $ sex : chr "c(2, 2, 1, 1, 1, 1, 2, 1, 1, 2,
2, 1, 2,
>2, 2,
>1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 2)" "c(1, 1, 1, 1, 1, 1, 1,
1, 2,
>2, 2,
>2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3)" "c(2, 2, 1,
1, 1,
>1, 2,
>1, 1, 2, 2, 1, 2, 2, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 2)"
"c(1,
>1, 1,
>1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3,
>3, 3)"
>... $ age : num 38.5 18 33.5 26 22.5 ...
> 
>#though I was hoping for something like
> 
>'data.frame': 29 obs. of  3 variables:
>$ group: chr  "A" "A" "A" "A" ...
>$ sex  : chr  "M" "F" "F" "M" ...
>$ age  : num  21.3 35.2 53.8 21 23.6 ...
>
>#What is wrong with my code?
>#Thank you for any help
>
>Best wishes 
>
>Alain
> 
> 
> 
>	[[alternative HTML version deleted]]
>
>______________________________________________
>R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>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.

R help - Feb 2015 - format selected columns in dataframe as character

[R] format selected columns in dataframe as character

[R] format selected columns in dataframe as character

[R] format selected columns in dataframe as character