【发布时间】：2022-01-09 03:08:48
【问题描述】：
问题与在 R 包中使用“for”循环和处理错误消息“未定义列”有关。
示例日期框架由 4 行和 10 列组成。库使用 magritter 和 dplyr。
library(magrittr)
library(dplyr)
date <- c ("2020-12-31", "2021-01-29", "2021-02-26", "2021-03-31")
v_1 <- c(66.39, 70.46, 69.37, 67.73)
v_2 <- c(14.16, 12.31, 13.07, 12.85)
v_3 <- c(14.37, 13.02, 13.09, 14.88)
v_4 <- c(0.94, 0.83, 0.74, 0.79)
v_5 <- c(0.42, 0.37, 0.33, 0.29)
v_6 <- c(1.51, 1.30, 1.14, 1.12)
v_7 <- c(1.84, 1.37, 1.91, 1.99)
v_8 <- c(0.16, 0.14, 0.14, 0.14)
v_9 <- c(0.21, 0.20, 0.21, 0.21)
raw.data <- data.frame(date, v_1, v_2, v_3, v_4, v_5, v_6, v_7, v_8, v_9)
变量 v_1 到 v_9 都被分配了一个优先级，即“高”、“中”或“低”
Priority <- c("High", "Medium", "Low")
High <- c("v_4", "v_7")
Medium <- c("v_2", "v_3", "v_9")
Low <- c("v_1", "v_5", "v_6", "v_8")
需要整齐/长格式的输出以包含 12 行和 3 列。
12 行：重复三次的日期变量。
3 列：日期、优先级和优先级总计。 （优先级总计是属于每个优先级类别的变量的逐行总和）
date Priority Priority_Total
1 2020-12-31 High 2.78
2 2021-01-29 High 2.20
3 2021-02-26 High 2.65
4 2021-03-31 High 2.78
5 2020-12-31 Medium 28.74
6 2021-01-29 Medium 25.53
7 2021-02-26 Medium 26.37
8 2021-03-31 Medium 27.94
9 2020-12-31 Low 68.48
10 2021-01-29 Low 72.27
11 2021-02-26 Low 70.98
12 2021-03-31 Low 69.28
使用粘贴和复制方法成功获得所需的输出。
请注意，“tmp”是一个临时工作空间。
pc_output <- NULL # Required output initialized
# High Priority
tmp <- raw.data[,c("date",High)] %>% # Selecting date and high priority variables.
mutate(Priority_Total=select(.,-1) %>% # Generating a priority total by summing across the rows.
apply(1,sum,na.rm=TRUE)) %>%
mutate(Priority="High") # Generating a priority category column containing value "High"
tmp <- tmp[,c("date","Priority","Priority_Total")] # Retaining the 3 required columns
pc_output <- rbind(pc_output,tmp) # Merging the derived result with pc_output
# The same procedure is used for medium and low priority variables
# Medium Priority
tmp <- raw.data[,c("date",Medium)] %>% # Selecting date and medium priority variables.
mutate(Priority_Total=select(.,-1) %>% # Generating a priority total by summing across the rows.
apply(1,sum,na.rm=TRUE)) %>%
mutate(Priority="Medium") # Generating a priority category column containing value "Medium"
tmp <- tmp[,c("date","Priority","Priority_Total")] # Retaining the 3 required columns
pc_output <- rbind(pc_output,tmp) # Merging the derived result with pc_output
# Low Priority
tmp <- raw.data[,c("date",Low)] %>% # Selecting date and low priority variables.
mutate(Priority_Total=select(.,-1) %>% # Generating a priority total by summing across the rows.
apply(1,sum,na.rm=TRUE)) %>%
mutate(Priority="Low") # Generating a priority category column containing value "Low"
tmp <- tmp[,c("date","Priority","Priority_Total")] # Retaining the 3 required columns
pc_output <- rbind(pc_output,tmp) # Merging the derived result with pc_output
rm(tmp) # Clearing the temporary work space
print(pc_output)
运行“粘贴和复制”方法以确保正确定义所有列。
但是当使用“for”循环时，遇到了“未定义列”的问题。
output <- NULL
for (i in (Priority)){
tmp <- raw.data[,c("date",i)] %>%
mutate(Priority_Total=select(.,-1) %>%
apply(1,sum,na.rm=TRUE)) %>%
mutate(Priority=i)
tmp <- tmp[,c("date","Priority","Priority_Total")]
output <- rbind(output,tmp)
}
消息：“[.data.frame(raw.data, , c("date", i)) 中的错误：选择了未定义的列”
【问题讨论】：