根据条件在数据框中插入行-Tidyverse方法 [英] Insert rows in dataframe based on condition - the Tidyverse way

问题描述

这是一个数据框

# 5 companies observed each day for 10 days
df <- tibble(
  company = rep(LETTERS[1:5], 10),
  value = rep(sample(100, 5), 10),
  date = rep(seq(as.Date("2020-01-01"), as.Date("2020-01-10"), 1), each = 5)
)
df

现在数据发生了一些变化，并且删除了一些公司E行.

Now something happens to the data and some of the company E rows are removed.

df_error <- df[-c(5, 10, 15, 20), ]
df_error

最简单的Tidyverse方法是加回E行.价值无所谓.E行的日期与其上方的D行相同.

What is the simplest Tidyverse way to add back the E rows. Value doesn't matter. The date of the E row is the same as the D row above it.

我从以下内容开始，不确定如何继续:

I started with the following and wasn't sure how to proceed:

# Find all D occurrences
e_idx <- which(df_error$company == "D")
e_idx

# If there is not an E in the next row, get the index. These need E rows below each index value. 
rows_need_e_below <- ifelse(df_error[e_idx + 1, 1] != "E", e_idx, NA)
rows_need_e_below

推荐答案

如果您知道自己的数据应包含"A"，到"E"您可以使用 complete 的公司:

If you know that your data should have "A" to "E" companies you can use complete :

tidyr::complete(df_error, date, company = LETTERS[1:5])

或更笼统地说:

unique_company <- c('A', 'B', 'C', 'D', 'E')
tidyr::complete(df_error, date, company = unique_company)

# A tibble: 50 x 3
#   date       company value
#   <date>     <chr>   <int>
# 1 2020-01-01 A          87
# 2 2020-01-01 B           5
# 3 2020-01-01 C          40
# 4 2020-01-01 D          67
# 5 2020-01-01 E          NA
# 6 2020-01-02 A          87
# 7 2020-01-02 B           5
# 8 2020-01-02 C          40
# 9 2020-01-02 D          67
#10 2020-01-02 E          NA
# … with 40 more rows

默认情况下， value 列是给定的 NA 值.如果要用特定值填充它，可以使用 complete 的 fill 参数.例如，要填充0，可以执行以下操作:

The value column is by default given NA value. If you want to fill it with specific value you can use fill parameter of complete. For example, to fill with 0's you can do :

tidyr::complete(df_error, date, company = unique_company, fill = list(value = 0))

这篇关于根据条件在数据框中插入行-Tidyverse方法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！