Question

目标：使用R，通过谷歌地图获取地址矢量的纬度/经度数据。方法：我从Tony Breyal的优秀代码开始：Geocoding in R with Google Maps并稍微修改它以适合我自己的目的（我需要函数返回一个SpatialPoints对象，其中包含所有地址和定义的投影字符串）。

所以我们有：

   library(RCurl)
   library(RJSONIO)
   library(maptools)

   #unchanged from Breyal's code
   construct.geocode.url <- function(address, return.call = "json", sensor = "false") {
     root <- "http://maps.google.com/maps/api/geocode/"
     u <- paste(root, return.call, "?address=", address, "&sensor=", sensor, sep = "")
     return(URLencode(u))
   }

  #obviously this would be better vectorized, but I left it in this form to help me
  #understand where the errors were coming from
  batchGeoCode <- function(address.list) {
    lat<-vector(mode="numeric",length=length(address.list))
    lng<-vector(mode="numeric",length=length(address.list))

    for(i in 1:length(address.list)){
      address<-address.list[i]
      u <- construct.geocode.url(address)
      doc <- getURL(u)
      x <- fromJSON(doc,simplify = FALSE)

      #I put the try in here just so I could see if it was always getting
      #hung on the same address or the same special character or the like
      errtest<-try(x$results[[1]]$geometry$location$lat)
      if(is(errtest, 'try-error')){
        lat[i]=0
        lng[i]=0
      }else{
        lat[i] <- x$results[[1]]$geometry$location$lat
        lng[i] <- x$results[[1]]$geometry$location$lng
      }
    }
    points.df<-data.frame(lat,lng)
    coordinates(points.df)=~lng+lat 
    points.sp<-SpatialPoints(coords=points.df,
      proj4string=CRS("+proj=longlat +datum=WGS84"))
    return(points.sp)
   }

   #some sample data that is enough to cause a fail for me--groceries and mini marts in 
   #South Seattle. All of these return a valid address when entered individually in 
   #Google Maps
   address.list<-c("T W YOUNG MARKET 7144 BEACON AVE S SEATTLE WA 98108",                       
    "RAINIER MARKET CTR 3625 1ST AVE S SEATTLE WA 98134",                        
    "JING JING ASIAN MARKET 12402 SE 38TH ST BELLEVUE WA 98006",                 
    "HILAL MARKET PLACE 15061 MILITARY RD S SEATAC WA 98188",                    
    "GUADALUPE MARKET 1111 SW 128TH ST BURIEN WA 98146",                         
    "JAMAL MARKET 14645 TUKWILA INTERNATIONAL BL TUKWILA WA 98168",              
    "C & D INTL MARKET  SEATTLE WA 98198",                                       
    "GUERRERO MARKET 17730 AMBAUM BLVD S # B SEATTLE WA 98148",                  
    "MI CASA MARKET 17174 116TH AVE SE RENTON WA 98058",                         
    "GUERRERO MARKET 17730 AMBAUM BLVD S # B SEATTLE WA 98148",                  
    "MI CASA MARKET 17174 116TH AVE SE RENTON WA 98058",                         
    "BILISEE MARKET 8300 RAINIER AVE S SEATTLE WA 98118",                        
    "ALI SEATAC INTL MARKET 16324 INTERNATIONAL BLVD SEATAC WA 98188",           
    "OCEAN MARKET 2119 RAINIER AVE S SEATTLE WA 98144",                          
    "RED APPLE MARKETS 9627 DES MOINES MEMORIAL DR SEATTLE WA 98108",            
    "ANKGOR MARKET 9660 16TH AVE SW SEATTLE WA 98106",                           
    "SIXTEENTH AVENUE GROCERY 9001 16TH AVE SW SEATTLE WA 98106",                
    "RAINIER ORIENTAL MARKET 9237 RAINIER AVE S SEATTLE WA 98118",               
    "CLEAN MACHINE LAUNDRYMAT  SEATTLE WA 98118",                                
    "HALIN GROCERY & DELI  SEATTLE WA 98118")    

   #call the function
   result<-batchGeoCode(address.list)

使用短列表可行，但随着列表超过15，我开始收到“无结果”回复。我很确定这是一个限制问题（例如Slow down Geocoding a batch of Address），但不太清楚如何在R中实现它，因此它符合此函数的特定需求。

提前致谢，

克里斯

Answer 1

一种方法是使用ggmap。

library(ggmap)

address.list<-c("T W YOUNG MARKET 7144 BEACON AVE S SEATTLE WA 98108",                       
            "RAINIER MARKET CTR 3625 1ST AVE S SEATTLE WA 98134",                        
            "JING JING ASIAN MARKET 12402 SE 38TH ST BELLEVUE WA 98006",                 
            "HILAL MARKET PLACE 15061 MILITARY RD S SEATAC WA 98188",                    
            "GUADALUPE MARKET 1111 SW 128TH ST BURIEN WA 98146",                         
            "JAMAL MARKET 14645 TUKWILA INTERNATIONAL BL TUKWILA WA 98168",              
            "C & D INTL MARKET  SEATTLE WA 98198",                                       
            "GUERRERO MARKET 17730 AMBAUM BLVD S # B SEATTLE WA 98148",                  
            "MI CASA MARKET 17174 116TH AVE SE RENTON WA 98058",                         
            "GUERRERO MARKET 17730 AMBAUM BLVD S # B SEATTLE WA 98148",                  
            "MI CASA MARKET 17174 116TH AVE SE RENTON WA 98058",                         
            "BILISEE MARKET 8300 RAINIER AVE S SEATTLE WA 98118",                        
            "ALI SEATAC INTL MARKET 16324 INTERNATIONAL BLVD SEATAC WA 98188",           
            "OCEAN MARKET 2119 RAINIER AVE S SEATTLE WA 98144",                          
            "RED APPLE MARKETS 9627 DES MOINES MEMORIAL DR SEATTLE WA 98108",            
            "ANKGOR MARKET 9660 16TH AVE SW SEATTLE WA 98106",                           
            "SIXTEENTH AVENUE GROCERY 9001 16TH AVE SW SEATTLE WA 98106",                
            "RAINIER ORIENTAL MARKET 9237 RAINIER AVE S SEATTLE WA 98118",               
            "CLEAN MACHINE LAUNDRYMAT  SEATTLE WA 98118",                                
            "HALIN GROCERY & DELI  SEATTLE WA 98118")

geocode(address.list, output="latlona")

R中使用Google地图进行批量地理编码会为许多查询返回“无结果”

1 个答案: