将命令给出的 position 编号/行号转换为 R 中的行名

Question

The which command in R gives the row number (or position number) but I have assigned names to those row numbers. How do I convert the row/position number into row names? Thanks!

Example:

 I have a data frame df: [,1] [,2] A 1 2 B 3 4 C 5 6 df1 = which(df[,1] > 0.0).

This gives position number 1,2 and 3. I want to convert it to A, B and C.

Answer 1

Assuming you have a named vector like in this example you could do:

vector <- c("a", "b", "c")
names(vector) <- c("AA", "BB", "CC")

names(which(vector=="b"))      

[1] "BB"