Question

我有一个数据框，其中包含一列字符串，如下所示：

    mydata <- c("-1.356670,35.355030",
            "-1.356670,35.355030", 
            "-1.356620,35.355890", 
            "-1.356930,35.358660", 
            "-1.357000,35.359060"
    )

    df <- data.frame(mydata)

我想将其转换为包含两列“ long和lat的数据帧，每列都是数字类型。这样做的最佳方法是什么？我尝试使用{{ 1}}，但似乎无法使其正常工作。

Answer 1

使用基数R，您可以执行以下操作：

df$Long <- as.numeric(sapply(strsplit(as.character(df$mydata), ","), function(x) x[1]))
df$Lat <- as.numeric(sapply(strsplit(as.character(df$mydata), ","), function(x) x[2]))

               mydata     Long      Lat
1 -1.356670,35.355030 -1.35667 35.35503
2 -1.356670,35.355030 -1.35667 35.35503
3 -1.356620,35.355890 -1.35662 35.35589
4 -1.356930,35.358660 -1.35693 35.35866
5 -1.357000,35.359060 -1.35700 35.35906

或者使用tstrsplit()中的data.table：

df$Long <- as.numeric(tstrsplit(df$mydata, ",")[[1]])
df$Lat <- as.numeric(tstrsplit(df$mydata, ",")[[2]])

还有@clmarquart提出的tstrsplit()中的data.table：

setDT(df)[, c("lat", "long") := tstrsplit(mydata, ",", fixed = TRUE)]

Answer 2

这可以在基数R的一行中完成：

public class CityInfoComparer:IComparer<CityInfo>
{
    private readonly IComparer<string> _baseComparer;

    public CityInfoComparer(IComparer<string> baseComparer)
    {
        _baseComparer = baseComparer;
    }

    public int Compare(CityInfo city1, CityInfo city2)
    {
        return _baseComparer.Compare(city1.CityName, city2.CityName);
    }
}


public class CityList
{
    public List<CityInfo> CityInfos { get; set; }

    public void Sort()
    {
        CityInfos.Sort( new CityInfoComparer(StringComparer.CurrentCulture));
    }

}

给予：

read.table(text = as.character(df$mydata), sep = ",", col.names = c("long", "lat"))

Answer 3

一种tidyverse解决方案。

library(tidyverse)

dat <- df %>%
  separate(mydata, into = c("Long", "Lat"), sep = ",", convert = TRUE)

# Print the data
dat
#       Long      Lat
# 1 -1.35667 35.35503
# 2 -1.35667 35.35503
# 3 -1.35662 35.35589
# 4 -1.35693 35.35866
# 5 -1.35700 35.35906

Answer 4

将strsplit与do.call一起使用，那么我们只需要分配列名

newdf=do.call(rbind.data.frame, strsplit(mydata,','))
names(newdf)=c('long','lat')
newdf
       long       lat
1 -1.356670 35.355030
2 -1.356670 35.355030
3 -1.356620 35.355890
4 -1.356930 35.358660
5 -1.357000 35.359060

将r数据框中的列字符串转换为数字

4 个答案: