Conversions for H*:M*:S*

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]
                        }
                )
        )
}
secondsToString <- function(x){
        unlist(
                lapply(x,
                        function(i){
                                fmt <- ''
                                if (i >= 3600)
                                        fmt <- '%H:%M:%S'
                                else if (i >= 60)
                                        fmt <- '%M:%S'
                                else
                                        fmt <- '%S'

                                i <- format(as.POSIXct(strptime("0:0:0","%H:%M:%S")) + round(i), fo
rmat=fmt)
                                i
                        }
                )
        )
}

milesToMeters <- function(miles=1){
        miles * 1609.344
}

metersToMiles <- function(meters=1){
        meters / 1609.344
}

toMPH <- function(secs=0,miles=NA,meters=NA){
        if (is.na(miles) && is.na(meters)) stop("Need miles or meters")
        miles <- ifelse (is.na(miles),miles <- metersToMiles(meters),miles)
        secs <- ifelse (is.character(secs), toSeconds(secs), secs)

        miles / (secs / 3600)
}

toKPH <- function(secs=0,miles=NA,meters=NA){
        if (is.na(miles) && is.na(meters)) stop("Need miles or meters")
        meters <- ifelse (is.na(meters),meters <- milesToMeters(miles),meters)
        secs <- ifelse (is.character(secs), toSeconds(secs), secs)

        (meters/1000) / (secs / 3600)
}

toMinPerMile <- function(secs=0,miles=NA,meters=NA){
        if (is.na(miles) && is.na(meters)) stop("Need miles or meters")
        miles <- ifelse (is.na(miles),miles <- metersToMiles(meters),miles)
        secs <- ifelse (is.character(secs), toSeconds(secs), secs)

        secondsToString(secs / miles)
}

unixunits <- function(fromU=NA,toU=NA){
        as.numeric(system(paste('units -t',fromU,toU),intern=TRUE))
}

Conversions for HMS

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]
                        }
                )
        )
}
secondsToString <- function(x){
        unlist(
                lapply(x,
                        function(i){
                                fmt <- ''
                                if (i >= 3600)
                                        fmt <- '%H:%M:%S'
                                else if (i >= 60)
                                        fmt <- '%M:%S'
                                else
                                        fmt <- '%S'

                                i <- format(as.POSIXct(strptime("0:0:0","%H:%M:%S")) + round(i), format=fmt)
                                i
                        }
                )
        )
}

milesToMeters <- function(miles=1){
        miles * 1609.344
}

metersToMiles <- function(meters=1){
        meters / 1609.344
}

toMPH <- function(secs=0,miles=NA,meters=NA){
        if (is.na(miles) && is.na(meters)) stop("Need miles or meters")
        miles <- ifelse (is.na(miles),miles <- metersToMiles(meters),miles)
        secs <- ifelse (is.character(secs), toSeconds(secs), secs)

        miles / (secs / 3600)
}

toKPH <- function(secs=0,miles=NA,meters=NA){
        if (is.na(miles) && is.na(meters)) stop("Need miles or meters")
        meters <- ifelse (is.na(meters),meters <- milesToMeters(miles),meters)
        secs <- ifelse (is.character(secs), toSeconds(secs), secs)

        (meters/1000) / (secs / 3600)
}

toMinPerMile <- function(secs=0,miles=NA,meters=NA){
        if (is.na(miles) && is.na(meters)) stop("Need miles or meters")
        miles <- ifelse (is.na(miles),miles <- metersToMiles(meters),miles)
        secs <- ifelse (is.character(secs), toSeconds(secs), secs)

        secondsToString(secs / miles)
}

unixunits <- function(fromU=NA,toU=NA){
        as.numeric(system(paste('units -t',fromU,toU),intern=TRUE))
}