Question

我正在使用R.我想将DataFrame-1转换为DataFrame-2

DataFrame-1
Variable1     Variable2
aa1           X1
aa1           Y2
aa1           Z1 
bb1           Y1
bb1           Y2

我想创建DataFrame-2，看起来像这样

Variable1     Variable2
aa1           X1, Y2, Z1
bb1           Y1, Y2

Answer 1

也许是这样的？

type DateTime=String

val la = List (ImageMetadata("12", "im 1 foo"), ImageMetadata ("13", "im 2 bar"), ImageMetadata ("23", "im 3 bar"))
val lb = List (ObjectMetadata("23", List ("o", "1")), ObjectMetadata ("12", List("o", "2")), ObjectMetadata ("17", List("o", "3")))

for (i <- la;
     o <- lb;
     if (i.time == o.time)) yield { ImageTypeMetadata (i.time, i.name, o.tags)}

res12: List[ImageTypeMetadata] = List(ImageTypeMetadata(12,im 1 foo,List(o, 2)), ImageTypeMetadata(23,im 3 bar,List(o, 1)))

Answer 2

希望这有帮助！

library(dplyr)

df1 <- df %>%
  group_by(Variable1) %>%
  summarise(Variable2 = paste(Variable2, collapse = ", ")) %>%
  data.frame()
df1

输出是：

  Variable1  Variable2
1       aa1 X1, Y2, Z1
2       bb1     Y1, Y2

示例数据：

df <- structure(list(Variable1 = c("aa1", "aa1", "aa1", "bb1", "bb1"
), Variable2 = c("X1", "Y2", "Z1", "Y1", "Y2")), .Names = c("Variable1", 
"Variable2"), class = "data.frame", row.names = c(NA, -5L))

Answer 3

这是cars数据集的示例：

split <- split(cars$dist, cars$speed)  

a <- list(length(split))
for (i in 1:length(split)){

  a[i] = paste(split[[i]], sep = "", collapse = ", ")}

df <- data.frame(x = labels(split), y = unlist(a))

输出如下：

    x                  y
1   4              2, 10
2   7              4, 22
3   8                 16
4   9                 10
5  10         18, 26, 34
6  11             17, 28
7  12     14, 20, 24, 28
8  13     26, 34, 34, 46
9  14     26, 36, 60, 80
10 15         20, 26, 54
11 16             32, 40
12 17         32, 40, 50
13 18     42, 56, 76, 84
14 19         36, 46, 68
15 20 32, 48, 52, 56, 64
16 22                 66
17 23                 54
18 24    70, 92, 93, 120
19 25                 85

Answer 4

使用spread和unite作为：

可以实现另一种可能的解决方案

library(tidyverse)
DataFrame1 %>% mutate(sl = row_number()) %>%
  spread(sl, Variable2, fill = "") %>%
  unite(col = "Variable2",-Variable1, sep = ",") %>%
  mutate(Variable2 = gsub("^,+|,+$", "", Variable2))

  Variable1 Variable2
1       aa1  X1,Y2,Z1
2       bb1     Y1,Y2

数据

DataFrame1 <- read.table(text = "Variable1 Variable2 aa1 X1 aa1 Y2 aa1 Z1 bb1 Y1 bb1 Y2", header = TRUE, stringsAsFactor = FALSE)

将多行转换为单列

4 个答案: