# R/num_to_well.R In platetools: Tools and Plots for Multi-Well Plates

#### Documented in num_to_well

```#' Converts numbers to well labels
#'
#' Converts numerical values to corresponding alpha-numeric well labels
#' for 6, 12, 24, 48, 96, 384 or 1536 well plates.
#' Note, it's advisable to specify the number of wells in `plate`.
#'
#' @param x Vector of numbers to be converted
#' @param plate Number of wells in complete plate (96 or 384)
#'
#' @return Vector of alpha-numeric well labels
#'
#' @export
#'
#' @examples
#' num_to_well(1:96)
#' num_to_well(1:96, plate = 384)
#'
#' nums <- c(1:10, 20:40, 60:96)
#' num_to_well(nums)

num_to_well <- function(x, plate = 96){

stopifnot(is.numeric(x))
if (any(x > plate)) {
stop("x cannot be greater than the number of wells in the plate",
call. = FALSE)
}
if (plate == 6L) {
rows <- LETTERS[1:2]
columns <- 1:3
} else if (plate == 12L) {
rows <- LETTERS[1:3]
columns <- 1:4
} else if (plate == 24L) {
rows <- LETTERS[1:4]
columns <- 1:6
} else if (plate == 48L) {
rows <- LETTERS[1:6]
columns <- 1:8
} else if (plate == 96L){
rows <- LETTERS[1:8]
columns <- 1:12
} else if (plate == 384L){
rows <- LETTERS[1:16]
columns <- 1:24
} else if (plate == 1536L){
first_26 <- LETTERS[1:26]
last_6 <- vector(length = 6)
for (i in 1:6){
last_6[i] <- paste(LETTERS[rep(i, 2)],
collapse = "")
}
rows <- c(first_26, last_6)
columns <- 1:48
} else stop("Plate needs to be 96, 384 or 1536")

# columns then rows for normal row-wise counting
combinations <-  expand.grid(columns, rows)
# but then have to reverse order to print in the normal way
out <- paste0(combinations[x, 2], formatC(combinations[x, 1], width = 2, flag = "0"))
return(out)
}
```

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platetools documentation built on June 3, 2021, 5:06 p.m.