带有layer_paths的R的ggvis工具提示

Question

我对ggvis中的工具提示函数有困难，因为我的等值线图。我在下面附上了我的代码。代码运行良好，没有工具提示功能。但如果我添加工具提示，只剩下新泽西的土地（见图）。其他州缺失。任何人都可以帮助看看，我如何修复它以添加其他部分添加工具提示功能？非常感谢！

###my data for example
mapdata<-data.frame(
  state=c("alabama","alaska","arizona","arkansas","california","colorado","connecticut","delaware","florida","georgia","hawaii","idaho","illinois","indiana","iowa","kansas","kentucky","louisiana","maine","maryland","massachusetts","michigan", "minnesota","mississippi","missouri","montana","nebraska","nevada","new hampshire","new jersey","new mexico","new york","north carolina","north dakota","ohio","oklahoma", "oregon","pennsylvania","rhode island","south carolina","south dakota","tennessee","texas","utah","vermont","virginia","washington","west virginia","wisconsin","wyoming"),
  revenue=runif(50,min=100,max=9000))

library(rgdal)   
library(ggplot2) 
library(ggvis)

url   <- "http://www2.census.gov/geo/tiger/GENZ2014/shp/cb_2014_us_state_20m.zip"
tf    <- tempfile()
td    <- tempdir()
download.file(url,tf, mode="wb")  
unzip(tf, exdir=td)                

usa <- readOGR(dsn=td, layer="cb_2014_us_state_20m")
shp <- usa[(!usa$STUSPS %in% c("AK","HI")),] 

df<- fortify(shp)                    
df<- merge(df,cbind(id=rownames(shp@data),shp@data),by="id")   
df$state <- tolower(df$NAME)                                                  
df<- merge(df,mapdata,by="state")  
df<- df[order(df$order),]       

####function for tooltip
gg<-df
gg$id<-1:nrow(gg)
values<-function(x){
  if(is.null(x)) return(NULL)
  row<-gg[gg$id==x$id,]
  paste0("State: ",row$state,"<br />",
         "Revenue: ", row$revenue, "<br />")
}
####ggvis choropleth
gg %>%
  group_by(group) %>%
  ggvis(~long, ~lat, key:=~id)  %>%
  hide_axis("x") %>% 
  hide_axis("y")%>%
  add_tooltip(values,"hover")%>%
  layer_paths(fill= ~revenue)

Answer 1

我正在四处寻找并意识到由于路径是来自数据集的多行信息，因此尝试使用工具提示的唯一行ID是没有意义的，就像我们通常使用{{1 }}

然后我看到了这个very nice ggvis tutorial，前进的道路对我来说变得更加清晰。您需要将工具提示基于分组变量，然后以某种方式将该组中许多行的信息提取到单个值。在其他选项中，您可以通过从组中取出第一行或在使用工具提示功能时仅使用key值来实现此目的。

以下是我的意思的示例，使用您在unique中使用的变量group来提取相关信息。

首先，使用group_by获取第一行：

head

或者，只需提取要显示的变量的values = function(x){ if(is.null(x)) return(NULL) row = head(gg[gg$group == unique(x$group), ], 1) paste0("State: ", row$state,"<br />", "Revenue: ", row$revenue, "<br />") } 值（每个州/组有一个）。这样就可以了，因为您只显示两个值：

unique

现在从values2 = function(x){ if(is.null(x)) return(NULL) row = gg[gg$group == unique(x$group), ] paste0("State: ", unique(row$state),"<br />", "Revenue: ", unique(row$revenue), "<br />") } 中取出key参数并使用其中一个新的工具提示函数。现在，交互式图表似乎工作正常。

ggvis