尝试遍历列以生成每个列的 table

Question

我有一个包含 10 列的 table。这些列具有以下名称："Month"、"Year"、"Advising"、"Hang Out"、"Food"、"Printing"、"Supplies"、"Studying"、"Lending Library"、"Other"

我想遍历每个原因列并创建一个 table 按 Y 中的月份和 X 中的年份以及该原因类别的总和进行分解。

我试图创建一个 for 循环并使用 sapply/lapply 函数族。但是，我不能移动过去 "Advising." 但是如果我运行我的功能在每个单独的列上它确实有效。

# Sample Data
AttendanceTab <- data.frame(Month = c("Oct", "Nov", "Oct", "Jan", "Feb", 
                                      "Mar", "May", "Oct"), 
                            Year = c( 2018, 2017, 2017, 2019, 2018, 2019, 
                                      2018, 2017), 
                            Advising = c(1, 1, 1, 0, 0, 1, 0, 0), 
                            Hang.Out = c(0, 0, 1, 0, 1, 1, 1, 0),
                            Food = c(1, 1, 1, 0, 0, 1, 1, 1))

attendance_summary <- function(ReasonName, FUN = sum) {
                    tapply(AttendanceTab[, ReasonName], 
                    AttendanceTab[,1:2], sum)
}

attendance_summary("Advising") 
attendance_summary("Hang.Out")
attendance_summary("Food")
attendance_summary("Printing")
attendance_summary("Supplies")
attendance_summary("Studying")
attendance_summary("Lending.Library")
attendance_summary("Other")

Complexes <- dim(AttendanceTab)[2]

reasons <- as.character(c("Advising", "Hang Out", "Food", 
          "Printing", "Supplies", "Studying", "Lending Library", 
          "Other"))

for(i in 1:Complexes) {
                    RR <- reasons[[i]]
                    ADSum <- attendance_summary(RR)
                    print(ADSum)
}

sapply(AttendanceTab, attendance_summary)
 #Also tried
sapply(reasons, attendance_summary)

for example reasons[[1]] 工作并给出适当的 table，但是当它移动到第二个 reasons 元素时，它 returns:

[.data.frame(attendance2, , ReasonName) 中的错误：选择了未定义的列

Answer 1

定义 reasons 时有错别字。在 AttendanceTab 中，您有 Hang.Out 列，在 reasons 中，您将其称为 Hang Out - space 而不是 .。为避免这种情况，您可以使用

reasons <- names(AttendanceTab)[-c(1:2)]
Complexes <- length(reasons)

尝试遍历列以生成每个列的 table

Trying to loop through columns to produce a table for each

for-loop

r

function

dataframe

sapply