R - 从数据框中的字符串中提取坐标

Question

我在 R 数据框中有这样的数据 - 这些都放在一个名为 SHAPE 的列中（下面只是摘录）：

"POINT (16.361866982751053 48.177421074512125)"
"POINT (16.30410258091979 48.16069903617549)"
"POINT (16.226971074542572 48.20539106235006)"
"POINT (16.36781410799229 48.25479849185693)"

我想提取坐标，以便将它们以数字格式放置在我的数据框的一列 "X" 和一列 "Y" 中。 挑战在于数字的长度并不总是相同。

结果应如下所示

第 X 列：

16.361866982751053
16.30410258091979
16.226971074542572
16.36781410799229

Y 列：

48.177421074512125
48.16069903617549
48.20539106235006
48.25479849185693

Answer 1

使用sub:

point <- "POINT (16.361866982751053 48.177421074512125)"
x <- sub("POINT \((\d+\.\d+) \d+\.\d+\)", "\1", point, perl=TRUE)
y <- sub("POINT \(\d+\.\d+ (\d+\.\d+)\)", "\1", point, perl=TRUE)

Demo

Answer 2

只是提供另一种解决方案，这次使用 strsplit() 和 lapply():

df <- data.frame(SHAPE = c("POINT (16.361866982751053 48.177421074512125)",
                           "POINT (16.30410258091979 48.16069903617549)",
                           "POINT (16.226971074542572 48.20539106235006)",
                           "POINT (16.36781410799229 48.25479849185693)"),
                 stringsAsFactors = F)

df[c("x", "y")] <- do.call(rbind, lapply(strsplit(df$SHAPE, "[()]"), function(col) {
  (parts <- unlist(strsplit(col[2], " ")))
}))
df

这会产生

                                          SHAPE                  x                  y
1 POINT (16.361866982751053 48.177421074512125) 16.361866982751053 48.177421074512125
2   POINT (16.30410258091979 48.16069903617549)  16.30410258091979  48.16069903617549
3  POINT (16.226971074542572 48.20539106235006) 16.226971074542572  48.20539106235006
4   POINT (16.36781410799229 48.25479849185693)  16.36781410799229  48.25479849185693
>

R - 从数据框中的字符串中提取坐标

R - Extract coordinates from String in dataframe

r

extract

dataframe

Demo