// TimeStepParallel does the same as TimeStep but with channels
func TimeStepParallel(R, V [][3]float64, L, M, h float64) ([][3]float64, [][3]float64) {
N := len(R)
A := make([][3]float64, N)
nR := make([][3]float64, N)
nV := make([][3]float64, N)
c := make(chan ForceReturn, N)
for i := 0; i < N; i++ {
go InternalForceParallel(i, R, L, c)
}
for n := 0; n < N; n++ {
info := <-c
i := info.i
Fi := info.F
A[i] = vector.Scale(Fi, 1.0/M)
nR[i] = space.PutInBox(verlet.NextR(R[i], V[i], A[i], h), L)
}
for i := 0; i < N; i++ {
go InternalForceParallel(i, nR, L, c)
}
for n := 0; n < N; n++ {
info := <-c
i := info.i
nFi := info.F
nAi := vector.Scale(nFi, 1.0/M)
nV[i] = verlet.NextV(V[i], A[i], nAi, h)
}
return nR, nV
}
// TimeStep evolves the system by one unit of time using the Velocity Verlet algorithm for molecular dynamics.
func TimeStep(R, V [][3]float64, L, M, h float64) ([][3]float64, [][3]float64) {
N := len(R)
A := make([][3]float64, N)
nR := make([][3]float64, N)
nV := make([][3]float64, N)
for i := 0; i < N; i++ {
Fi := InternalForce(i, R, L)
A[i] = vector.Scale(Fi, 1.0/M)
nR[i] = space.PutInBox(verlet.NextR(R[i], V[i], A[i], h), L)
}
for i := 0; i < N; i++ {
nFi := InternalForce(i, nR, L)
nAi := vector.Scale(nFi, 1.0/M)
nV[i] = verlet.NextV(V[i], A[i], nAi, h)
}
return nR, nV
}