Extract value of cell from each column, where row value matches value in vector

Question

I have a vector of years (97). I also have a data frame with "year" and 97 columns of values.

Year	1
2020	5.663
2021	9.344

vector (97): 2050, 2045, 2047 ......

For column 1 I need to extract the value of the first year of the vector, 2050, for column 2 the second value of the vector, 2045, etc..

I'm not sure how to do this, I thought maybe a loop would be best?

Answer 1

I may have misunderstood; is this your expected output?

set.seed(123)
df <- data.frame(Year = c(2020, 2021, 2022),
                 Col1 = rnorm(3),
                 Col2 = rnorm(3),
                 Col3 = rnorm(3))
df
#>   Year       Col1       Col2       Col3
#> 1 2020 -0.5604756 0.07050839  0.4609162
#> 2 2021 -0.2301775 0.12928774 -1.2650612
#> 3 2022  1.5587083 1.71506499 -0.6868529

years_vec <- c(2022, 2021)

output <- list()
for (i in seq_along(years_vec)) {
  output[[i]] <- df[match(years_vec[i], df$Year), i + 1]
}
unlist(output)
#> [1] 1.5587083 0.1292877

^{Created on 2023-06-28 with reprex v2.0.2}