解析网页并转换为data.frame

时间:2014-03-05 04:28:01

标签: r gis

我正试图从这个网站上搜集材料:http://www.appliedsolutions.org/site/308/Local-Government/Local-Government-Affiliates

具体来说,我有兴趣从页面源代码第598行附近的javascript中提取值:

 {
            "title": 'Coconino County',
            "lat": '35.7714',
            "lng": '-111.5111',
            "description": 'Coconino County, AZ <br/> <a href="http://www.coconino.az.gov/" target="_blank"> http://www.coconino.az.gov/</a> <br/>  '
        }

    ,

         {
            "title": 'City of Flagstaff',
            "lat": '35.1981',
            "lng": '-111.6506',
            "description": 'City of Flagstaff, AZ <br/> <a href="http://www.flagstaff.az.gov/   " target="_blank"> http://www.flagstaff.az.gov/   </a> <br/>  '
        }

理想情况下,我想将“title”,“lat”和“lng”值带入R data.frame

我使用R中的readLines函数来读取页面,但是在减少html以隔离我需要的数据方面遇到了麻烦。

1 个答案:

答案 0 :(得分:5)

这是使用RSelenium包的一种方式。

## Get RSelenium going and navigate to page, retrieve source
require(RSelenium)
RSelenium::checkForServer()
RSelenium::startServer()
remDr <- remoteDriver()
remDr$open()
remDr$setImplicitWaitTimeout(3000)
remDr$navigate("http://www.appliedsolutions.org/site/308/Local-Government/Local-Government-Affiliates")

编辑:每个@jdharrison建议更简单

appData <- remDr$executeScript("return markers;")

dat <- do.call(rbind.data.frame, appData)
dat <- dat[,c("title","lat","lng")]

> head(dat)
        lat       lng               title
   35.7714 -111.5111     Coconino County
   35.1981 -111.6506   City of Flagstaff
   34.8697 -111.7603      City of Sedona
   34.6503 -112.4147      Yavapai County
     32.64 -117.0833 City of Chula Vista
   38.8056 -123.0161  City of Cloverdale