根据条件语句从其他列填充R中的新列

Question

I have a data frame (data.frame(test)) in R with the following information.

Columns1 | Column2 | Column3
1 | 11 | 33
3 | 34 | 56 
4 | 24 | 23
5 | 74 | 64 
3 | 45 | 52
2 | 54 | 53
1 | 76 | 92

I am trying to create a new column that is populated by the data in columns 2 and 3 based on a conditional statement of column 1.

I cannot seem to figure out how to write the appropriate conditional.

if (test$column1 == 3 || test$column1 == 2 || test$column1 == 1) {
test$Newcolumn = test$column1
} else {
  test$NewColumn = test$column2
}

The final result should look like this:

Columns1 | Column2 | Column3 | NewColumn 
1 | 11 | 33 | 11
3 | 34 | 56 | 33
4 | 24 | 23 | 23
5 | 74 | 64 | 64
3 | 45 | 52 | 45
2 | 54 | 53 | 54
1 | 76 | 92 | 76

Answer 1

With dplyr , assuming mydf is your dataframe:

mydf %>% mutate(newColumn = ifelse(column1 %in% 1:3, column2, column3)) -> res

I assumed there is a typo in your question and you intended to assign column2 value to newColumn in case the condition is met.

Answer 2

解决方案“像ifelse这样简单的ifelse（在％c（1,2,3）中测试$ column1％，测试$ column2，测试$ column3）” - 由joel.wilson工作。