看起来网站阻止了Curl的直接访问。
library(XML)
library(RCurl)
theurl <- "http://www.london2012.com/medals/medal-count/"
page <- getURL(theurl)
page # fail
[1] "<HTML><HEAD>\n<TITLE>Access Denied</TITLE>\n</HEAD><BODY>\n<H1>Access Denied</H1>\n \nYou don't have permission to access \"http://www.london2012.com/medals/medal-count/\" on this server.<P>\nReference #18.358a503f.1343590091.c056ae2\n</BODY>\n</HTML>\n"
让我们试着看看我们是否可以直接从表中访问它。
page <- readHTMLTable(theurl)
那里没有运气Error in htmlParse(doc) : error in creating parser for http://www.london2012.com/medals/medal-count/
你如何将这张桌子放入R？
更新：响应评论和玩弄，伪造用户代理字符串以获取内容。但readHTMLtable返回错误。
page <- getURLContent(theurl, useragent="Mozilla/5.0 (Windows NT 6.1; rv:15.0) Gecko/20120716 Firefox/15.0a2")
答案 0 :(得分：12)
看起来这样有效：
rr <- readHTMLTable(page,header=FALSE)
rr2 <- setNames(rr[[1]],
c("rank","country","gold","silver","bronze","junk","total"))
rr3 <- subset(rr2,select=-junk)
## oops, numbers all got turned into factors ...
tmpf <- function(x) { as.numeric(as.character(x)) }
rr3[,-2] <- sapply(rr3[,-2],tmpf)
head(rr3)
## rank country gold silver bronze total
## 1 1 People's Republic of China 6 4 2 12
## 2 2 United States of America 3 5 3 11
## 3 3 Italy 2 3 2 7
## 4 4 Republic of Korea 2 1 2 5
## 5 5 France 2 1 1 4
## 6 6 Democratic People's Republic of Korea 2 0 1 3
with(rr3,dotchart(total,country))
答案 1 :(得分：12)
这是我使用正则表达式提出的。非常具体，绝对不比使用其他答案中使用的readHTMLTable更好。更多内容表明你可以在R：
# file <- "~/Documents/R/medals.html"
# page <- readChar(file,file.info(file)$size)
library(RCurl)
theurl <- "http://www.london2012.com/medals/medal-count/"
page <- getURLContent(theurl, useragent="Mozilla/5.0 (Windows NT 6.1; rv:15.0) Gecko/20120716 Firefox/15.0a2")
# Remove html tags:
page <- gsub("<(.|\n)*?>","",page)
# Remove newlines and tabs:
page <- gsub("\\n","",page)
# match table:
page <- regmatches(page,regexpr("(?<=Total).*(?=Detailed)",page,perl=TRUE))
# Extract country+medals+rank
codes <-regmatches(page,gregexpr("\\d+[^\\r]*\\d+",page,perl=TRUE))[[1]]
codes <- codes[seq(1,length(codes)-2,by=2)]
# Extract country and medals:
Names <- gsub("\\d","",codes)
Medals <- sapply(regmatches(codes,gregexpr("\\d",codes)),function(x)x[(length(x)-2):length(x)])
# Create data frame:
data.frame(
Country = Names,
Gold = as.numeric(Medals[1,]),
Silver = as.numeric(Medals[2,]),
Bronze = as.numeric(Medals[3,]))
输出：
Country Gold Silver Bronze
1 People's Republic of China 6 4 2
2 United States of America 3 5 3
3 Italy 2 3 2
4 Republic of Korea 2 1 2
5 France 2 1 1
6 Democratic People's Republic of Korea 2 0 1
7 Kazakhstan 2 0 0
8 Australia 1 1 1
9 Brazil 1 1 1
10 Hungary 1 1 1
11 Netherlands 1 1 0
12 Russian Federation 1 0 3
13 Georgia 1 0 0
14 South Africa 1 0 0
15 Japan 0 2 3
16 Great Britain 0 1 1
17 Colombia 0 1 0
18 Cuba 0 1 0
19 Poland 0 1 0
20 Romania 0 1 0
21 Taipei (Chinese Taipei) 0 1 0
22 Azerbaijan 0 0 1
23 Belgium 0 0 1
24 Canada 0 0 1
25 Republic of Moldova 0 0 1
26 Norway 0 0 1
27 Serbia 0 0 1
28 Slovakia 0 0 1
29 Ukraine 0 0 1
30 Uzbekistan 0 0 1