Calculating distances from latitude and longitude coordinates in R

Question

I am trying to calculate distance between one location and all other locations from their latitudes and longitudes.

I have been using distanceTrack from the argosfilter

Answer 1

 earthDist <- function (lon1, lat1, lon2, lat2){
    rad <- pi/180
    a1 <- lat1 * rad
    a2 <- lon1 * rad
    b1 <- lat2 * rad
    b2 <- lon2 * rad
    dlon <- b2 - a2
    dlat <- b1 - a1
    a <- (sin(dlat/2))^2 + cos(a1) * cos(b1) * (sin(dlon/2))^2
    c <- 2 * atan2(sqrt(a), sqrt(1 - a))
    R <- 6378.145
    d <- R * c
    return(d)
}

earthDist(lon[1], lat[1], lon, lat)