Got plotting working

julia/propagator.jl

@@ -1,3 +1,15 @@
+"""
+Maximum ΔV that a spacecraft can impulse for a given single time step
+"""
+function max_ΔV(duty_cycle::Float64,
+                num_thrusters::Int,
+                max_thrust::Float64,
+                tf::Float64,
+                t0::Float64,
+                mass::Float64)
+  return duty_cycle*num_thrusters*max_thrust*(tf-t0)/mass
+end
+
 """
 This function propagates the spacecraft forward in time 1 Sim-Flanagan step (of variable length of time),
 applying a thrust in the center.
@@ -26,11 +38,64 @@ A convenience function for using spacecraft. Note that this function outputs a s
 """
 function prop_one(ΔV_unit::Vector{Float64},
                   state::Vector{Float64},
-                  craft::sc,
+                  craft::Sc,
                   μ::Float64,
                   time::Float64)
   state, mass =  prop_one(ΔV_unit, state, craft.duty_cycle, craft.num_thrusters, craft.max_thrust,
                           craft.mass, craft.mass_flow_rate, μ, time)
-  return state, sc(mass, craft.mass_flow_rate, craft.max_thrust, craft.num_thrusters, craft.duty_cycle)
+  return state, Sc(mass, craft.mass_flow_rate, craft.max_thrust, craft.num_thrusters, craft.duty_cycle)
 end
 
+"""
+This propagates over a given time period, with a certain number of intermediate steps
+"""
+function prop(ΔV_units::Vector{Vector{Float64}},
+              state::Vector{Float64},
+              duty_cycle::Float64,
+              num_thrusters::Int,
+              max_thrust::Float64,
+              mass::Float64,
+              mass_flow_rate::Float64,
+              μ::Float64,
+              time::Float64,
+              n::Int)
+
+  if length(ΔV_units) != n
+    throw(ExceptionError("Bad number of ΔV vectors"))
+  end
+
+  for i in 1:n
+    state, mass = prop_one(ΔV_units[i], state, duty_cycle, num_thrusters, max_thrust, mass,
+                           mass_flow_rate, μ, time/n)
+  end
+
+  return state, mass
+
+end
+
+"""
+The same function, using Scs
+"""
+function prop(ΔV_units::Vector{Vector{Float64}},
+              state::Vector{Float64},
+              craft::Sc,
+              μ::Float64,
+              time::Float64,
+              n::Int)
+
+  if length(ΔV_units) != n
+    throw(ExceptionError("Bad number of ΔV vectors"))
+  end
+
+  states = state'
+  masses = craft.mass
+
+  for i in 1:n
+    state, craft = prop_one(ΔV_units[i], state, craft, μ, time/n)
+    states = [states; state']
+    masses = [masses, craft.mass]
+  end
+
+  return states, masses
+
+end