How to convert playtime to seconds in R - r

Question

I have a vector as follows:
playtimes <- c("1H18M20S", "1H27M5S", "18M27S", "56M38S", "21S")
and I want to convert these to playtimes in second. For example, the resulting vector would be something like this:
playtimeInSeconds <- c(4700, 5225, 1107, 3398, 21)
Im having trouble with separating the strings correctly based on the H, M and S. I wrote the following that works for the playtimes under 1 hour
minutes <- gsub("M.*", "", playtime)
seconds <- gsub(".*M", "", playtime) %>%
gsub("S", "", .)
totalPlaytime <- as.numeric(minutes)*60 + as.numeric(seconds)
But Im not sure how to tackle the H portion of some strings.

Answer 1

You could strsplit and adapt the length of the list elements reversely to 3 which allows you to use sapply to get a matrix where you apply the matrix product %*%.
m <- sapply(strsplit(p, 'H|M|S'), \(x) as.double(rev(`length<-`(rev(x), 3))))
res <- as.vector(t(replace(m, is.na(m), 0)) %*% rbind(3600, 60, 1))
res
# [1] 4700 5225 1107 3398 21

Answer 2

interesting problem. here is a solution that potentially could be more efficient but does the job
# function from https://www.statworx.com/de/blog/strsplit-but-keeping-the-delimiter/
strsplit <- function(x,
split,
type = "remove",
perl = FALSE,
...) {
if (type == "remove") {
# use base::strsplit
out <- base::strsplit(x = x, split = split, perl = perl, ...)
} else if (type == "before") {
# split before the delimiter and keep it
out <- base::strsplit(x = x,
split = paste0("(?<=.)(?=", split, ")"),
perl = TRUE,
...)
} else if (type == "after") {
# split after the delimiter and keep it
out <- base::strsplit(x = x,
split = paste0("(?<=", split, ")"),
perl = TRUE,
...)
} else {
# wrong type input
stop("type must be remove, after or before!")
}
return(out)
}
# convert to seconds
to_seconds <- c(H = 60 * 60,
M = 60,
S = 1)
get_seconds <- function(value, unit) {
value * to_seconds[unit]
}
# example vector
playtimes <- c("1H18M20S", "1H27M5S", "18M27S", "56M38S", "21S")
# extract time parts
times <- strsplit(playtimes,
split = "[A-Z]",
type = "after")
times
#> [[1]]
#> [1] "1H" "18M" "20S"
#>
#> [[2]]
#> [1] "1H" "27M" "5S"
#>
#> [[3]]
#> [1] "18M" "27S"
#>
#> [[4]]
#> [1] "56M" "38S"
#>
#> [[5]]
#> [1] "21S"
# calculate each time in seconds
sapply(times,
function(t) {
# split numeric and unit part
t_split <- strsplit(x = t,
split = "[A-Z]",
type = "before")
# calculate seconds for each unit part
times_in_seconds <- get_seconds(value = as.numeric(sapply(t_split, `[`, 1)),
unit = sapply(t_split, `[`, 2))
# sum of all parts
sum(times_in_seconds)
})
#> [1] 4700 5225 1107 3398 21

Answer 3

I followed the example given in the 3rd answer here and made the following
playtime <- sapply(playtime, function(x){paste(paste(rep(0, 3 - str_count(x, '[0-9]+')), collapse = ' '), x)})
totalPlaytime <- time_length(hms(playtime))
Short, sweet, and checks for potential errors where the playtime is less that 1 hr or less than 1 min.