go - How can I move between 2 gps points at a set speed? -

i'm trying create function let me give 2 arguments, new location , speed travel @ (in meters / second)

it looks this:

func (l *location) move(newloc *location, speed float64) {     r := 6371.0 // kilometers     lat1 := l.latitude * math.pi / 180     lat2 := l.longitude * math.pi / 180     difflat := (newloc.latitude - l.latitude) * math.pi / 180     difflon := (newloc.longitude - l.longitude) * math.pi / 180      := math.sin(difflat/2)*math.sin(difflat/2) +         math.cos(lat1)*math.cos(lat2)*math.sin(difflon/2)*math.sin(difflon/2)     c := 2 * math.atan2(math.sqrt(a), math.sqrt(1-a))      distancetomove := r * c // distance travel in straight line, in kilometers   } 

the thing i'm having trouble thinking of formula make latitude, start @ current position, , end @ new position on set amount of time.

so person changed latitude 56.65 58.12 , told travel @ 1.3m/s how can accomplish this. thanks.

if understand question, goal compute intermediate points between 2 location, starting 1 location , going second 1 using specified speed.

if i'm correct, following how first solution. if can improve this, i'd appreciate.

on proj4 documentation, can find lot of information on how compute distance between 2 points.

starting points reach b given speed (m/s), means compute each seconds point a' @ distance m on line ab.

in more algorithmic way (based on vincenty's formula):

func (l *location) move(newloc *location, speed float64) location {     azimutha, azimuthb, d := inversevincenty(l, newloc)      // use direct vincenty's formula.     // here transform speed correct value     // without transformation, since speed in m/s,     // resulting point @ speed(m) distance l.     res := directvincenty(l, speed, azimutha)      // res shall contain new point.     return res }  func main() {     // init , b , speed values.     c := // conserve position.     t := time.tick(1* time.second)     stop := false; !stop; {         select {             case <- t:             c = c.move(b, speed)             case // here break condition:                 stop = true         }     } } 

i think thats start, comment appreciate on answer.