问题
Even though my Windows 7 locale settings specify using "," as a decimal separator, R and RStudio give me a "." separator. Is there any way to change this? Note the "LC_NUMERIC=C" setting in the locale below: this seems to be forced by R or RStudio.
As I am in the middle of a long project, I am unwilling to change right away to R 3.0 and the last RStudio version. Does anybody know is there is any change regarding the decimal separator issue in these versions?
I am using prettyNum to solve the problem for single numbers, but I don't know how to use it on a table.
sessionInfo() R version 2.15.3 (2013-03-01) Platform: x86_64-w64-mingw32/x64 (64-bit)
locale:
[1] LC_COLLATE=Spanish_Argentina.1252 LC_CTYPE=Spanish_Argentina.1252
[3] LC_MONETARY=Spanish_Argentina.1252 LC_NUMERIC=C
[5] LC_TIME=Spanish_Argentina.1252
attached base packages:
[1] grid splines stats graphics grDevices utils datasets methods
[9] base
other attached packages:
[1] ascii_2.1 randomForest_4.6-7 pander_0.3.3 fpc_2.1-5
[5] flexmix_2.3-10 mclust_4.0 cluster_1.14.3 MASS_7.3-23
[9] Gmisc_0.5.0.0 testthat_0.7 boot_1.3-7 rms_3.6-3
[13] miscTools_0.6-16 stringr_0.6.2 Hmisc_3.10-1 survival_2.37-2
[17] lattice_0.20-13 xtable_1.7-1 pixmap_0.4-11 RColorBrewer_1.0-5
[21] ade4_1.5-1
loaded via a namespace (and not attached):
[1] digest_0.6.3 evaluate_0.4.3 modeltools_0.2-19 stats4_2.15.3
[5] tools_2.15.3
回答1:
The decimal separator used by the read.table and write.table functions (and most of their cousins) is set with "dec" parameter. read.csv2 is a special case where the default for dec is "," and the field separator ("sep") is set to ";".
You can change the output from R printing, plotting and the actions of the as.character function. You change it from its default with:
options(OutDec= ",") # read ?options
print( pi )
#[1] 3,141593
options(OutDec= ",") # restore default value
This will NOT cause R to handle numeric input from the console differently. That is hard-coded to "." as the decimal separator.
If you applied a text function to a table object, you would be possibly coercing from a 'numeric' to a 'character' mode, since table objects in R inherit from the "matrix" class.
回答2:
Why do you want to use "," as decimal separator, in that case how R will interprate this R expression
x <- c(2,3) # (two vectors or one).
So, I assume that you just want to override the default decimal separator to print an output and in this case, I think prettyNum is the right tool.
require(plyr)
head(numcolwise(prettyNum)(iris, dec = ","))
## Sepal.Length Sepal.Width Petal.Length Petal.Width
## 1 5,1 3,5 1,4 0,2
## 2 4,9 3 1,4 0,2
## 3 4,7 3,2 1,3 0,2
## 4 4,6 3,1 1,5 0,2
## 5 5 3,6 1,4 0,2
## 6 5,4 3,9 1,7 0,4
回答3:
Based on the fact that you want to use it with (Pandoc) markdown as far as I can see from the blog comment where you referenced this question, I would also suggest to give a try to my pander package:
> library(pander)
> panderOptions('decimal.mark', ',')
> panderOptions('table.split.table', Inf)
> pander(head(iris))
-------------------------------------------------------------------
Sepal.Length Sepal.Width Petal.Length Petal.Width Species
-------------- ------------- -------------- ------------- ---------
5,1 3,5 1,4 0,2 setosa
4,9 3 1,4 0,2 setosa
4,7 3,2 1,3 0,2 setosa
4,6 3,1 1,5 0,2 setosa
5 3,6 1,4 0,2 setosa
5,4 3,9 1,7 0,4 setosa
-------------------------------------------------------------------
Or PHP Markdown Extra syntax for easier usage with knitr:
> pandoc.table(head(iris), style = 'rmarkdown')
| Sepal.Length | Sepal.Width | Petal.Length | Petal.Width | Species |
|:--------------:|:-------------:|:--------------:|:-------------:|:---------:|
| 5,1 | 3,5 | 1,4 | 0,2 | setosa |
| 4,9 | 3 | 1,4 | 0,2 | setosa |
| 4,7 | 3,2 | 1,3 | 0,2 | setosa |
| 4,6 | 3,1 | 1,5 | 0,2 | setosa |
| 5 | 3,6 | 1,4 | 0,2 | setosa |
| 5,4 | 3,9 | 1,7 | 0,4 | setosa |
来源：https://stackoverflow.com/questions/16384836/how-to-set-as-decimal-separator-with-r