使用基於兩列的 left_join 在 R 中不起作用

Question

我正在嘗試將包含left_join字母的數據left_join到主數據left_join 。 聯接應基於兩列。 每行只有一列包含值，因為它們來自不同的模型。

這里的主要數據幀：

main_df<-structure(list(crop = c("B", "B", "B", "B", "B", "B", "B", "B", 
"B", "A", "A", "A", "A", "A", "A", "A", "A", "A", "C", "C", "C", 
"C", "C", "C", "C", "C", "C"), till = c("X", "X", "X", "Y", "Y", 
"Y", "Z", "Z", "Z", "X", "X", "X", "Y", "Y", "Y", "Z", "Z", "Z", 
"X", "X", "X", "Y", "Y", "Y", "Z", "Z", "Z"), GW = c("250", "100", 
"500", "250", "100", "500", "250", "100", "500", "250", "100", 
"500", "250", "100", "500", "250", "100", "500", "250", "100", 
"500", "250", "100", "500", "250", "100", "500"), dm = c(12.492780040282, 
21.2330087520355, 9.08920058839951, 9.6579014126203, 32.3208262815535, 
10.6259628492133, 6.13043260006999, 49.6628012967183, 28.8896483162288, 
14.8279966222885, 11.5590504143496, 23.7186742486867, 22.8598403733191, 
8.59025110732551, 20.8781551231343, 34.6812252760796, 25.056901935212, 
11.9791387922734, 2.98603520945085, 20.768615091017, 5.68987327841495, 
35.6382624005007, 24.1315098558383, 32.3442728999024, 35.5586316123229, 
8.36256345081252, 6.06606303991154)), row.names = c(NA, -27L), class = c("tbl_df", 
"tbl", "data.frame"))

而這里的 cld 數據框：

cld_df<-structure(list(till = c("Z", "Y", "X", NA, NA, NA, "Z", "X", 
"Y"), .group = c(" a ", "  b", "  b", " a ", " ab", "  b", " a ", 
" ab", "  b"), crop = c("B", "B", "B", "C", "C", "C", "A", "A", 
"A"), GW = c(NA, NA, NA, "500", "250", "100", NA, NA, NA)), row.names = c(NA, 
-9L), class = c("tbl_df", "tbl", "data.frame"))

cld 位於名為“.group”的列內。 將列保留為字符並將它們轉換為因子都會導致空列：

main_df%>% mutate(till=as.factor(till),GW=as.factor(GW),crop=as.factor(crop)) %>%  
left_join(cld_df%>%mutate(till=as.factor(till),GW=as.factor(GW),crop=as.factor(crop)))

Answer 1

這是你需要的嗎？

main_df %>%
  left_join(select(cld_df, crop, till, .group), by = c("crop", "till")) %>%
  left_join(select(cld_df, crop, GW, .group), by = c("crop", "GW")) %>%
  mutate(.group = coalesce(.group.x, .group.y)) %>%
  select(-.group.x, -.group.y) %>%
  print(n=99)
# # A tibble: 27 x 5
#    crop  till  GW       dm .group
#    <chr> <chr> <chr> <dbl> <chr> 
#  1 B     X     250   12.5  "  b" 
#  2 B     X     100   21.2  "  b" 
#  3 B     X     500    9.09 "  b" 
#  4 B     Y     250    9.66 "  b" 
#  5 B     Y     100   32.3  "  b" 
#  6 B     Y     500   10.6  "  b" 
#  7 B     Z     250    6.13 " a " 
#  8 B     Z     100   49.7  " a " 
#  9 B     Z     500   28.9  " a " 
# 10 A     X     250   14.8  " ab" 
# 11 A     X     100   11.6  " ab" 
# 12 A     X     500   23.7  " ab" 
# 13 A     Y     250   22.9  "  b" 
# 14 A     Y     100    8.59 "  b" 
# 15 A     Y     500   20.9  "  b" 
# 16 A     Z     250   34.7  " a " 
# 17 A     Z     100   25.1  " a " 
# 18 A     Z     500   12.0  " a " 
# 19 C     X     250    2.99 " ab" 
# 20 C     X     100   20.8  "  b" 
# 21 C     X     500    5.69 " a " 
# 22 C     Y     250   35.6  " ab" 
# 23 C     Y     100   24.1  "  b" 
# 24 C     Y     500   32.3  " a " 
# 25 C     Z     250   35.6  " ab" 
# 26 C     Z     100    8.36 "  b" 
# 27 C     Z     500    6.07 " a "