R按条件添加缺少的行[重复]

Question

我有一个包含计数数据的数据集 ('DF1')。它看起来像这样：

Species	Date	Site	n
AMCR	6/1/2021	SVC	14
AMCR	6/1/2021	BMA	1
AMCR	6/7/2021	SVA	2
AMCR	6/15/2021	SVA	9
AMCR	6/21/2021	SVA	18
AMCR	6/29/2021	SVA	18

但是，我的研究实际上有九个“站点”（SVC、BMA、SVA、BMC、TMA、TMC、SRA、SRC 和 MCC），并且每个站点都在相同的五个日期（2021 年 6 月 1 日）收集数据，2021 年 6 月 8 日、2021 年 6 月 15 日、2021 年 6 月 21 日和 2021 年 6 月 29 日）。 DF1 仅显示“n”中有计数的行，但如果没有计数，我希望数据框为每个站点的每个日期填充零计数，使其看起来像这样：

Species	Date	Site	n
AMCR	6/1/2021	SVC	14
AMCR	6/7/2021	SVC	0
AMCR	6/15/2021	SVC	0
AMCR	6/21/2021	SVC	0
AMCR	6/29/2021	SVC	0
AMCR	6/1/2021	BMA	1
AMCR	6/7/2021	BMA	0
AMCR	6/15/2021	BMA	0
AMCR	6/21/2021	BMA	0
AMCR	6/29/2021	BMA	0
AMCR	6/1/2021	SVA	0
AMCR	6/7/2021	SVA	2
AMCR	6/15/2021	SVA	9
AMCR	6/21/2021	SVA	18
AMCR	6/29/2021	SVA	18
AMCR	6/1/2021	BMC	0
AMCR	6/7/2021	BMC	0
AMCR	6/15/2021	BMC	0
AMCR	6/21/2021	BMC	0
AMCR	6/29/2021	BMC	0
AMCR	6/1/2021	TMA	0
AMCR	6/7/2021	TMA	0
AMCR	6/15/2021	TMA	0
AMCR	6/21/2021	TMA	0
AMCR	6/29/2021	TMA	0
AMCR	6/1/2021	TMC	0
AMCR	6/7/2021	TMC	0
AMCR	6/15/2021	TMC	0
AMCR	6/21/2021	TMC	0
AMCR	6/29/2021	TMC	0
AMCR	6/1/2021	SRA	0
AMCR	6/7/2021	SRA	0
AMCR	6/15/2021	SRA	0
AMCR	6/21/2021	SRA	0
AMCR	6/29/2021	SRA	0
AMCR	6/1/2021	SRC	0
AMCR	6/7/2021	SRC	0
AMCR	6/15/2021	SRC	0
AMCR	6/21/2021	SRC	0
AMCR	6/29/2021	SRC	0
AMCR	6/1/2021	MCC	0
AMCR	6/7/2021	MCC	0
AMCR	6/15/2021	MCC	0
AMCR	6/21/2021	MCC	0
AMCR	6/29/2021	MCC	0

有没有办法通过检查这些日期和站点组合是否不存在来添加计数为 0 的行？

谢谢。

Answer 1

dplyr/tidyr

library(dplyr)
library(tidyr)
dat %>%
  complete(Species, Date, Site, fill = list(n = 0))
# # A tibble: 15 x 4
#    Species Date      Site      n
#    <chr>   <chr>     <chr> <dbl>
#  1 AMCR    6/1/2021  BMA       1
#  2 AMCR    6/1/2021  SVA       0
#  3 AMCR    6/1/2021  SVC      14
#  4 AMCR    6/15/2021 BMA       0
#  5 AMCR    6/15/2021 SVA       9
#  6 AMCR    6/15/2021 SVC       0
#  7 AMCR    6/21/2021 BMA       0
#  8 AMCR    6/21/2021 SVA      18
#  9 AMCR    6/21/2021 SVC       0
# 10 AMCR    6/29/2021 BMA       0
# 11 AMCR    6/29/2021 SVA      18
# 12 AMCR    6/29/2021 SVC       0
# 13 AMCR    6/7/2021  BMA       0
# 14 AMCR    6/7/2021  SVA       2
# 15 AMCR    6/7/2021  SVC       0

基础 R

dat2 <- merge(dat, do.call(expand.grid, lapply(dat[,1:3], unique)), by = names(dat)[1:3], all = TRUE)
dat2
#    Species      Date Site  n
# 1     AMCR  6/1/2021  BMA  1
# 2     AMCR  6/1/2021  SVA NA
# 3     AMCR  6/1/2021  SVC 14
# 4     AMCR 6/15/2021  BMA NA
# 5     AMCR 6/15/2021  SVA  9
# 6     AMCR 6/15/2021  SVC NA
# 7     AMCR 6/21/2021  BMA NA
# 8     AMCR 6/21/2021  SVA 18
# 9     AMCR 6/21/2021  SVC NA
# 10    AMCR 6/29/2021  BMA NA
# 11    AMCR 6/29/2021  SVA 18
# 12    AMCR 6/29/2021  SVC NA
# 13    AMCR  6/7/2021  BMA NA
# 14    AMCR  6/7/2021  SVA  2
# 15    AMCR  6/7/2021  SVC NA
dat2$n <- ifelse(is.na(dat2$n), 0, dat2$n)
dat2
#    Species      Date Site  n
# 1     AMCR  6/1/2021  BMA  1
# 2     AMCR  6/1/2021  SVA  0
# 3     AMCR  6/1/2021  SVC 14
# 4     AMCR 6/15/2021  BMA  0
# 5     AMCR 6/15/2021  SVA  9
# 6     AMCR 6/15/2021  SVC  0
# 7     AMCR 6/21/2021  BMA  0
# 8     AMCR 6/21/2021  SVA 18
# 9     AMCR 6/21/2021  SVC  0
# 10    AMCR 6/29/2021  BMA  0
# 11    AMCR 6/29/2021  SVA 18
# 12    AMCR 6/29/2021  SVC  0
# 13    AMCR  6/7/2021  BMA  0
# 14    AMCR  6/7/2021  SVA  2
# 15    AMCR  6/7/2021  SVC  0

---

数据

dat <- structure(list(Species = c("AMCR", "AMCR", "AMCR", "AMCR", "AMCR", "AMCR"), Date = c("6/1/2021", "6/1/2021", "6/7/2021", "6/15/2021", "6/21/2021", "6/29/2021"), Site = c("SVC", "BMA", "SVA", "SVA", "SVA", "SVA"), n = c(14L, 1L, 2L, 9L, 18L, 18L)), class = "data.frame", row.names = c(NA, -6L))