通过SPARQL使用R XML编码问题 [英] Encoding problems with R XML via SPARQL

问题描述

我遇到了R的SPARQL软件包的编码问题.我正在运行以下代码:

I running into an encoding problem with the SPARQL package for R. I'm running the following code:

library(SPARQL)

rights_query <- '
PREFIX dc:  <http://purl.org/dc/elements/1.1/>
PREFIX edm: <http://www.europeana.eu/schemas/edm/>
PREFIX ore: <http://www.openarchives.org/ore/terms/>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

SELECT DISTINCT ?edmrights ?provider (COUNT(*) as ?count)
WHERE {
?agg rdf:type ore:Aggregation .
?agg edm:rights ?edmrights .
#?agg dc:rights ?dcrights .
?agg edm:dataProvider ?provider .

?proxy ore:proxyIn ?agg .
?proxy edm:type "IMAGE" .
}
GROUP BY ?edmrights ?provider
ORDER BY ?provider DESC(?count)'

eur <- "http://europeana.ontotext.com/sparql"

eur_data <- SPARQL(eur, rights_query)$results
write.csv(eur_data, "results.csv")

代码运行时没有任何错误或警告，但是在RStudio和CSV中查看的结果数据帧显然存在编码问题.

The code runs without any errors or warnings, however the resulting data frame as viewed in RStudio, as well as the CSV, clearly have encoding problems.

例如，最后一个应该部分是西里尔字母:Чувашский государственный художественный музей / Chouvashia State Art Museum

For example, the last ought to be partly Cyrillic: Чувашский государственный художественный музей / Chouvashia State Art Museum

但是结果如下:ЧÑваÑÑкий гоÑÑдаÑÑÑвеннÑй ÑÑдожеÑÑвеннÑй мÑзей / Chouvashia State Art Museum

我已经检查了SPARQL查询返回的XML.它通过XML验证，并包含正确的"UTF-8"编码声明. R XML包(R SPARQL包用来将XML输出解析为数据帧的方式)应该认识到这一点，对吧?

I've inspected the XML returned by the SPARQL query. It passes XML validation, and contains the proper "UTF-8" encoding declaration. The R XML package (which is what the R SPARQL package uses to parse XML output into a data frame) ought to recognize this, right?

您可以检查整个 XML输出，以及 CSV文件.我正在OS X Mavericks上通过RStudio运行R 3.1.0.我已将RStudio的默认字符编码设置为UTF-8.

You can inspect the entire XML output, as well as the CSV file. I am running R 3.1.0 via RStudio, on OS X Mavericks. I have set RStudio's default character encoding to UTF-8.

推荐答案

而不是SPARQL.R，我将考虑以下内容: ...

instead of SPARQL.R in this case I would consider something like the following: ...

Sys.setenv(LANG="ru")
library(RCurl)
library(XML)
url=<SPARQL endpoint query URL>
xquery=<your query which may contain windows-1251 chars on Windows 7+>
#xquery=iconv(xquery,"CP1251","UTF-8") #it may be required on Windows 7+
param="query"
extrastr=""
resp <- getURL(url = paste(url, '?', param, '=', gsub('\\+','%2B',URLencode(xquery,reserved=TRUE)), extrastr, sep=""), httpheader = c(Accept="application/sparql-results+xml"),.encoding="UTF-8")
xmlResp=xmlParse(resp)
xmlRespRoot=xmlRoot(xmlResp)
nRows=xmlSize(xmlRespRoot[2]$results)
if (nRows>0){
    xRespList=NULL
    for(i in 1:nRows){
    xrow=NULL
    tmprow=(xmlRespRoot[2]$results)[i]$result
    nCols=xmlSize(tmprow)
    for(j in 1:nCols){
        xrow=cbind(xrow,xmlValue(tmprow[j]$binding,encoding="UTF-8"))
    }
    xRespList=rbind(xRespList,xrow)
    }
}

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