Description Usage Arguments Details Value Author(s) See Also Examples
View source: R/subNonStandardCharacters.R
First convert to ASCII, stripping standard
accents and special characters. Then find
the first and last character not in
standardCharacters
and replace all
between them with replacement
. For
example, a string like "Ruben" where "e"
carries an accent and is mangled by some
software would become something like
"Rub_n" using the default values for
standardCharacters
and
replacement
.
1 2 3 4 5 6 7 8 9 |
x |
character vector in which it is desired
to find the first and last character not
in |
standardCharacters |
a character vector of acceptable characters to keep. |
replacement |
a character to replace the subtring starting and ending with
characters not in |
gsubList |
list of lists of |
... |
optional arguments passed to |
1. for(il in 1:length(gsubList))x <- gsub( gsubList[[il]][["pattern"]], gsublist[[il]][['replacement']], x)
2. x <- stringi::stri_trans_general(x, "Latin-ASCII")
3. nx <- length(x)
4. x. <- strsplit(x, "", ...)
5. for(ix in 1:nx) find the first and last
standardCharacters
in x.[ix] and substitute replacement
for everything in
between.
NOTES:
** To find the elements of x that have changed, use either
subNonStandardCharacters(x) != x
or
grep(replacement, subNonStandardCharacters(x))
, where
replacement
is the replacement
argument = "_" by
default.
** On 13 May 2013 Jeff Newmiller at the University of California, Davis, wrote, 'I think it is a fools errand to think that you can automatically "normalize" arbitrary Unicode characters to an ASCII form that everyone will agree on.' (This was a reply on r-help@r-project.org, subject: "Re: [R] Matching names with non- English characters".)
** On 2014-12-15 Ista Zahn suggested
stri_trans_general
. (This was a reply on
r-help@r-project.org, subject: "[R] Comparing Latin characters
with and without accents?".)
a character vector with everthing between the first and last
character not in standardCharacters
replaced by
replacement
.
Spencer Graves with thanks to Jeff Newmiller, who described this
as a "fool's errand", Milan Bouchet-Valat, who directed me to
iconv
, and Ista Zahn, who suggested
stri_trans_general
.
sub
, strsplit
,
grepNonStandardCharacters
,
subNonStandardNames
subNonStandardNames
iconv
in the base
package does some conversion, but is not
consistent across platforms, at least
using R 3.1.2 on 2015-01.25.
stri_trans_general
seems better.
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 | ##
## 1. Consider Names = Ruben, Avila and Jose, where "e" and "A" in
## these examples carry an accent. With the default values
## for standardCharacters and replacement, these might be
## converted to something like Rub_n, _vila, and Jos_, with
## different software possibly mangling the names differently.
## (The standard checks for R packages in an English locale
## complains about non-ASCII characters, because they are
## not portable.)
##
nonstdNames <- c('Ra`l', 'Ra`', '`l', 'Torres, Raul',
"Robert C. \\Bobby\\\\", NA, '', ' ',
'$12', '12%')
# confusion in character sets can create
# names like Names[2]
Name2 <- subNonStandardCharacters(nonstdNames)
str(Name2)
# check
Name2. <- c('Ra_l', 'Ra_', '_l', nonstdNames[4],
'Robert C. "Bobby"', NA, '', ' ',
'$12', '12%')
str(Name2.)
all.equal(Name2, Name2.)
##
## 2. Example from iconv
##
icx <- c("Ekstr\xf8m", "J\xf6reskog",
"bi\xdfchen Z\xfcrcher")
icx2 <- subNonStandardCharacters(icx)
# check
icx. <- c('Ekstrom', 'Joreskog', 'bisschen Zurcher')
all.equal(icx2, icx.)
|
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