Is there a way to convert mm:ss.00 to seconds.00?

Question

I\'ve got some performance time data in mm:ss.00 format (i.e. 02:15.45, or 00:34.58). R is recognizing the variable as a factor, but I\'d like to convert each performance t

Answer 1

Look into strptime. Specifically

t = "02:15.45"
(as.numeric(as.POSIXct(strptime(t, format = "%M:%OS"))) - 
    as.numeric(as.POSIXct(strptime("0", format = "%S"))))

This will work, but is possibly a little awkward (doing it this way mostly because of POSIXct's annoying automatic unit conversion...)

Answer 2

library(lubridate)
df$variable<- hms(df$variable)
df$variable<- as.numeric(df$variable)

make it a one-liner is ok as well. Works like a charm for me.
I hope this helps.

Answer 3

Here's one I've used for a number of years. It's vectorized, too.

toSeconds <- function(x){
   if (!is.character(x)) stop("x must be a character string of the form H:M:S")
   if (length(x)<=0)return(x)

   unlist(
      lapply(x,
         function(i){
            i <- as.numeric(strsplit(i,':',fixed=TRUE)[[1]])
            if (length(i) == 3) 
               i[1]*3600 + i[2]*60 + i[3]
            else if (length(i) == 2) 
               i[1]*60 + i[2]
            else if (length(i) == 1) 
               i[1]
         }  
      )  
   )  
} 

And the reverse (preserves fractional seconds to the number of digits requested:

secondsToString <- function(x,digits=2){
   unlist(
      lapply(x,
         function(i){
            # fractional seconds
            fs <- as.integer(round((i - round(i))*(10^digits)))
            fmt <- ''
            if (i >= 3600)
               fmt <- '%H:%M:%S'
            else if (i >= 60)
            fmt <- '%M:%S'
            else
               fmt <- '%OS'

            i <- format(as.POSIXct(strptime("0:0:0","%H:%M:%S")) + i, format=fmt)
            if (fs > 0)
               sub('[0]+$','',paste(i,fs,sep='.'))
            else
               i
         }
      )
   )
}

Answer 4

You can do this easily with the Lubridate package. If you use the format "h:m:s" you can convert the variable to a lubridate object with

hms("12:12:54")

And then convert it to seconds with

seconds(hms("12:12:54"))

Here is a link to the lubridate article in JSS

http://www.jstatsoft.org/v40/i03/paper

Answer 5

I am not that much comfortable so i don't know if there is any builtin function available, but i have worked out this code.

mmss_to_ss <- function  (string)
{
  mmss <- strsplit (string, ":", T)
  mm <- as.numeric (mmss[[1]][1])
  ss <- as.numeric (mmss[[1]][2])
  return (mm * 60 + ss)
}

This will accept a time string in mm:ss format and return second values. The code can be easily modified to convert from hh:mm:ss to seconds also.

Answer 6

Using lubridate package (part of tidyverse):

library(lubridate)
period_to_seconds(hms("12:12:54"))