From 5035c0eca2e54af83154ac91463788917176231a Mon Sep 17 00:00:00 2001
From: Dave LeCompte <tsmaster@gmail.com>
Date: Fri, 5 Mar 2021 15:56:24 -0800
Subject: [PATCH 1/3] Begin porting LUNAR to python

got much of the structure moved around, but the flow isn't right yet. Probably will refactor to be object-oriented.
---
 59 Lunar LEM Rocket/lunar.bas       |   6 +-
 59 Lunar LEM Rocket/python/lunar.py | 206 ++++++++++++++++++++++++++++
 2 files changed, 209 insertions(+), 3 deletions(-)
 create mode 100644 59 Lunar LEM Rocket/python/lunar.py

diff --git a/59 Lunar LEM Rocket/lunar.bas b/59 Lunar LEM Rocket/lunar.bas
index 17b8ed11..db07b0a5 100644
--- a/59 Lunar LEM Rocket/lunar.bas	
+++ b/59 Lunar LEM Rocket/lunar.bas	
@@ -18,7 +18,7 @@
 170 IF T<1E-03 THEN 150
 180 S=T: IF M>=N+S*K THEN 200
 190 S=(M-N)/K
-200 GOSUB 420: IF I<=O THEN 340
+200 GOSUB 420: IF I<=0 THEN 340
 210 IF V<=0 THEN 230
 220 IF J<0 THEN 370
 230 GOSUB 330: GOTO 160
@@ -26,12 +26,12 @@
 250 V=V+G*S: L=L+S
 260 W=3600*V: PRINT "ON MOON AT";L;"SECONDS - IMPACT VELOCITY";W;"MPH" 
 274 IF W<=1.2 THEN PRINT "PERFECT LANDING!": GOTO 440 
-280 IF W<=10 THEN PRINT "GOOD LANDING (COULD RE BETTER)":GOTO 440 
+280 IF W<=10 THEN PRINT "GOOD LANDING (COULD BE BETTER)":GOTO 440 
 282 IF W>60 THEN 300
 284 PRINT "CRAFT DAMAGE... YOU'RE STRANDED HERE UNTIL A RESCUE" 
 286 PRINT "PARTY ARRIVES. HOPE YOU HAVE ENOUGH OXYGEN!" 
 288 GOTO 440
-300 PRINT "SORRY THERE NERE NO SURVIVORS. YOU BLOW IT!"
+300 PRINT "SORRY THERE WERE NO SURVIVORS. YOU BLEW IT!"
 310 PRINT "IN FACT, YOU BLASTED A NEW LUNAR CRATER";W*.227;"FEET DEEP!"
 320 GOTO 440
 330 L=L+S: T=T-S: M=M-S*K: A=I: V=J: RETURN
diff --git a/59 Lunar LEM Rocket/python/lunar.py b/59 Lunar LEM Rocket/python/lunar.py
new file mode 100644
index 00000000..da2329ef
--- /dev/null
+++ b/59 Lunar LEM Rocket/python/lunar.py	
@@ -0,0 +1,206 @@
+"""
+LUNAR
+
+Lunar landing simulation
+
+Ported by Dave LeCompte
+"""
+
+PAGE_WIDTH = 64
+
+
+def print_centered(msg):
+    spaces = " " * ((PAGE_WIDTH - len(msg)) // 2)
+    print(spaces + msg)
+
+
+def print_header(title):
+    print_centered(title)
+    print_centered("CREATIVE COMPUTING  MORRISTOWN, NEW JERSEY")
+    print()
+    print()
+    print()
+
+
+def print_instructions():
+    print("THIS IS A COMPUTER SIMULATION OF AN APOLLO LUNAR")
+    print("LANDING CAPSULE.")
+    print()
+    print()
+    print("THE ON-BOARD COMPUTER HAS FAILED (IT WAS MADE BY")
+    print("XEROX) SO YOU HAVE TO LAND THE CAPSULE MANUALLY.")
+    print()
+
+def print_intro():
+    print("SET BURN RATE OF RETRO ROCKETS TO ANY VALUE BETWEEN")
+    print("0 (FREE FALL) AND 200 (MAXIMUM BURN) POUNDS PER SECOND.")
+    print("SET NEW BURN RATE EVERY 10 SECONDS.")
+    print()
+    print("CAPSULE WEIGHT 32,500 LBS; FUEL WEIGHT 16,500 LBS.")
+    print()
+    print()
+    print()
+    print("GOOD LUCK")
+    print()
+
+def show_landing(l, v):
+    w = 3600 * v
+    print("ON MOON AT {l} SECONDS - IMPACT VELOCITY {w} MPH")
+    if w < 1.2:
+        print("PERFECT LANDING!")
+    elif w < 10:
+        print("GOOD LANDING (COULD BE BETTER)")
+    elif w <= 60:
+        print("CRAFT DAMAGE... YOU'RE STRANDED HERE UNTIL A RESCUE")
+        print("PARTY ARRIVES. HOPE YOU HAVE ENOUGH OXYGEN!")
+    else:
+        print("SORRY THERE WERE NO SURVIVORS. YOU BLEW IT!")
+        print("IN FACT, YOU BLASTED A NEW LUNAR CRATER {w*.227:.4f} FEET DEEP!")
+    end_sim()
+
+        
+def update_physics():
+    # line 330
+    elapsed_time += delta_t
+    time_to_prompt -= delta_t
+    m = m - delta_t * k
+    a = i
+    v = j
+    return
+
+def update_burn():
+    # line 420
+    q = delta_t * k / m
+    j = (v +
+         g * delta_t +
+         z * (-q - q*q/2 - q**3/3 - q**4/4 - q**5/5))
+    i = (a -
+         g * delta_t * delta_t/2 -
+         v * delta_t +
+         z * delta_t * (q / 2 +
+                        q ** 2 / 6 +
+                        q ** 3 / 12 +
+                        q ** 4 / 20 +
+                        q ** 5 / 30))
+
+    return q,j,i
+
+def end_sim():
+    print()
+    print()
+    print()
+    print("TRY AGAIN??")
+
+
+def prompt_for_burn():
+    # line 150
+    print("{l}\t{a}\t{int(5280*(a-int(a)))}\t{3600 * v}\t{m-n}")
+    k = input()
+
+def run_simulation():
+    print()
+    print("SEC\tMI + FT\tMPH\tLB FUEL\tBURN RATE")
+    print()
+    
+    elapsed_time = 0
+    a = 120
+    v = 1 
+    m = 33000 # mass of capsule with fuel
+    n = 16500 # mass of capsule without fuel
+    g = 1e-3
+    z = 1.8
+
+    k = prompt_for_burn()
+    time_to_prompt = 10
+
+    while True:
+        # line 160
+        if M-N < 1e-3:
+            # line 240
+            print(f"FUEL OUT AT {elapsed_time} SECONDS")
+            delta_t = (-v + math.sqrt(v*v + 2*a*g)) / g
+            v += g * delta_t
+            elapsed_time += delta_t
+            show_landing(elapsed_time, v)
+            return
+
+        if t < 1e-3:
+            k = prompt_for_burn()
+            continue
+
+        # line 180
+        delta_t = time_to_prompt
+        if m < n + delta_t * k:
+            delta_t = (m-n) / k
+            
+        # line 200
+        q,j,i = update_burn()
+
+        if i <= 0:
+            # line 340
+            while True:
+                if delta_t < 5e-3:
+                    show_landing(elapsed_time, v)
+                #line 350
+                d = v + math.sqrt(v*v + 2*a*(g-z*k/m))
+                delta_t = 2 * a / d
+                update_burn()
+                update_physics()
+
+        else:
+            # line 210
+            if ((v > 0) and (j < 0)):
+                GOTO 370
+            # line 230
+            update_physics()
+
+
+
+        
+        
+
+
+def main():
+    print_header("LUNAR")
+    print_instructions()
+    while True:
+        print_intro()
+        run_simulation()
+        
+
+"""
+120 L=0
+130 PRINT: PRINT "SEC","MI + FT","MPH","LB FUEL","BURN RATE":PRINT 
+140 A=120:V=1:M=33000:N=16500:G=1E-03:Z=1.8
+150 PRINT L,INT(A);INT(5280*(A-INT(A))),3600*V,M-N,:INPUT K:T=10 
+160 IF M-N<1E-03 THEN 240
+170 IF T<1E-03 THEN 150
+180 S=T: IF M>=N+S*K THEN 200
+190 S=(M-N)/K
+200 GOSUB 420: IF I<=O THEN 340
+210 IF V<=0 THEN 230
+220 IF J<0 THEN 370
+230 GOSUB 330: GOTO 160
+240 PRINT "FUEL OUT AT";L;"SECONDS":S=(-V+SQR(V*V+2*A*G))/G
+250 V=V+G*S: L=L+S
+260 W=3600*V: PRINT "ON MOON AT";L;"SECONDS - IMPACT VELOCITY";W;"MPH" 
+274 IF W<=1.2 THEN PRINT "PERFECT LANDING!": GOTO 440 
+280 IF W<=10 THEN PRINT "GOOD LANDING (COULD RE BETTER)":GOTO 440 
+282 IF W>60 THEN 300
+284 PRINT "CRAFT DAMAGE... YOU'RE STRANDED HERE UNTIL A RESCUE" 
+286 PRINT "PARTY ARRIVES. HOPE YOU HAVE ENOUGH OXYGEN!" 
+288 GOTO 440
+300 PRINT "SORRY THERE NERE NO SURVIVORS. YOU BLOW IT!"
+310 PRINT "IN FACT, YOU BLASTED A NEW LUNAR CRATER";W*.227;"FEET DEEP!"
+320 GOTO 440
+330 L=L+S: T=T-S: M=M-S*K: A=I: V=J: RETURN
+340 IF S<5E-03 THEN 260
+350 D=V+SQR(V*V+2*A*(G-Z*K/M)):S=2*A/D
+360 GOSUB 420: GOSUB 330: GOTO 340
+370 W=(1-M*G/(Z*K))/2: S=M*V/(Z*K*(W+SQR(W*W+V/Z)))+.05:GOSUB 420
+380 IF I<=0 THEN 340
+390 GOSUB 330: IF J>0 THEN 160
+400 IF V>0 THEN 370
+410 GOTO 160
+
+"""

From 71a9c4828235073f1c783fad817540497d59a983 Mon Sep 17 00:00:00 2001
From: Dave LeCompte <tsmaster@gmail.com>
Date: Sat, 6 Mar 2021 14:15:40 -0800
Subject: [PATCH 2/3] WIP port LUNAR to python

refactored a bunch, did some debugging - more testing, cleanup remains.
---
 59 Lunar LEM Rocket/python/lunar.py | 384 ++++++++++++++++++++++------
 1 file changed, 308 insertions(+), 76 deletions(-)

diff --git a/59 Lunar LEM Rocket/python/lunar.py b/59 Lunar LEM Rocket/python/lunar.py
index da2329ef..93a73082 100644
--- a/59 Lunar LEM Rocket/python/lunar.py	
+++ b/59 Lunar LEM Rocket/python/lunar.py	
@@ -6,8 +6,34 @@ Lunar landing simulation
 Ported by Dave LeCompte
 """
 
+import collections
+import math
+
+
 PAGE_WIDTH = 64
 
+COLUMN_WIDTH = 2
+SECONDS_WIDTH = 4
+MPH_WIDTH = 6
+ALT_MI_WIDTH = 6
+ALT_FT_WIDTH = 4
+MPH_WIDTH = 6
+FUEL_WIDTH = 8
+BURN_WIDTH = 10
+
+SECONDS_LEFT = 0
+SECONDS_RIGHT = SECONDS_LEFT + SECONDS_WIDTH
+ALT_LEFT = SECONDS_RIGHT + COLUMN_WIDTH
+ALT_MI_RIGHT = ALT_LEFT + ALT_MI_WIDTH
+ALT_FT_RIGHT = ALT_MI_RIGHT + COLUMN_WIDTH + ALT_FT_WIDTH
+MPH_LEFT = ALT_FT_RIGHT + COLUMN_WIDTH
+MPH_RIGHT = MPH_LEFT + MPH_WIDTH
+FUEL_LEFT = MPH_RIGHT + COLUMN_WIDTH
+FUEL_RIGHT = FUEL_LEFT + FUEL_WIDTH
+BURN_LEFT = FUEL_RIGHT + COLUMN_WIDTH
+BURN_RIGHT = BURN_LEFT + BURN_WIDTH
+
+PhysicalState = collections.namedtuple('PhysicalState', ['velocity', 'altitude'])
 
 def print_centered(msg):
     spaces = " " * ((PAGE_WIDTH - len(msg)) // 2)
@@ -21,8 +47,35 @@ def print_header(title):
     print()
     print()
 
+def add_rjust(line, s, pos):
+    # adds a new field to a line right justified to end at pos
+    
+    s = str(s)
+    slen = len(s)
+    if len(line) + slen > pos:
+        new_len = pos - slen
+        line = line[:new_len]
+    if len(line) + slen < pos:
+        spaces = " " * (pos - slen - len(line))
+        line = line + spaces
+    return line + s
+
+def add_ljust(line, s, pos):
+    # adds a new field to a line left justified starting at pos
+    
+    s = str(s)
+    slen = len(s)
+    if len(line) > pos:
+        line = line[:pos]
+    if len(line) < pos:
+        spaces = " " * (pos - len(line))
+        line = line + spaces
+    return line + s
+
 
 def print_instructions():
+    # Somebody had a bad experience with Xerox.
+    
     print("THIS IS A COMPUTER SIMULATION OF AN APOLLO LUNAR")
     print("LANDING CAPSULE.")
     print()
@@ -43,9 +96,9 @@ def print_intro():
     print("GOOD LUCK")
     print()
 
-def show_landing(l, v):
-    w = 3600 * v
-    print("ON MOON AT {l} SECONDS - IMPACT VELOCITY {w} MPH")
+def show_landing(sim_clock, capsule):
+    w = 3600 * capsule.v
+    print(f"ON MOON AT {sim_clock.elapsed_time} SECONDS - IMPACT VELOCITY {w} MPH")
     if w < 1.2:
         print("PERFECT LANDING!")
     elif w < 10:
@@ -55,104 +108,248 @@ def show_landing(l, v):
         print("PARTY ARRIVES. HOPE YOU HAVE ENOUGH OXYGEN!")
     else:
         print("SORRY THERE WERE NO SURVIVORS. YOU BLEW IT!")
-        print("IN FACT, YOU BLASTED A NEW LUNAR CRATER {w*.227:.4f} FEET DEEP!")
+        print(f"IN FACT, YOU BLASTED A NEW LUNAR CRATER {w*.227:.4f} FEET DEEP!")
     end_sim()
 
+
+def show_out_of_fuel(sim_clock, capsule):
+    # line 240
+    print(f"FUEL OUT AT {sim_clock.elapsed_time} SECONDS")
+    delta_t = (-capsule.v + math.sqrt(capsule.v ** 2 + 2 *
+                                      capsule.a * capsule.g)) / capsule.g
+    capsule.v += capsule.g * delta_t
+    sim_clock.advance(delta_t)
+    show_landing(sim_clock, capsule)
+
+def format_line_for_report(t, miles, feet, velocity, fuel, burn_rate, is_header):
+    line = add_rjust("", t, SECONDS_RIGHT)
+    line = add_rjust(line, miles, ALT_MI_RIGHT)
+    line = add_rjust(line, feet, ALT_FT_RIGHT)
+    line = add_rjust(line, velocity, MPH_RIGHT)
+    line = add_rjust(line, fuel, FUEL_RIGHT)
+    if is_header:
+        line = add_rjust(line, burn_rate, BURN_RIGHT)
+    else:
+        line = add_ljust(line, burn_rate, BURN_LEFT)
+    return line
+
+class Capsule:
+    def __init__(self,
+                 altitude = 120,
+                 velocity = 1,
+                 mass_with_fuel = 33000,
+                 mass_without_fuel = 16500,
+                 g = 1e-3,
+                 z = 1.8):
+        self.a = altitude # in miles above the surface
+        self.v = velocity # downward
+        self.m = mass_with_fuel
+        self.n = mass_without_fuel
+        self.g = g
+        self.z = z
+        self.fuel_per_second = 0
+
+    def remaining_fuel(self):
+        return self.m - self.n
+
+    def is_out_of_fuel(self):
+        return self.remaining_fuel() < 1e-3
+
+    def update_state(self, sim_clock, delta_t, new_state):
+        # line 330
+        sim_clock.advance(delta_t)
+        self.m = self.m - delta_t * self.fuel_per_second
+        self.a = new_state.altitude
+        self.v = new_state.velocity
+
+    def fuel_time_remaining(self):
+        # extrapolates out how many seconds we have at the current fuel burn rate
+        assert(self.fuel_per_second > 0)
+        return self.remaining_fuel() / self.fuel_per_second
+
+    def predict_motion(self, delta_t):
+        # Perform an Euler's Method numerical integration of the equations of motion.
+
+        # line 420
+        q = delta_t * self.fuel_per_second / self.m
+
+        # new velocity
+        new_velocity = (self.v +
+                        self.g * delta_t +
+                        self.z * (-q -
+                                  q ** 2 / 2 -
+                                  q ** 3 / 3 -
+                                  q ** 4 / 4 -
+                                  q ** 5 / 5))
+
+        # new altitude
+        new_altitude = (self.a -
+                        self.g * delta_t ** 2 / 2 -
+                        self.v * delta_t +
+                        self.z * delta_t * (q / 2 +
+                                            q ** 2 / 6 +
+                                            q ** 3 / 12 +
+                                            q ** 4 / 20 +
+                                            q ** 5 / 30))
+
         
-def update_physics():
-    # line 330
-    elapsed_time += delta_t
-    time_to_prompt -= delta_t
-    m = m - delta_t * k
-    a = i
-    v = j
-    return
+        return PhysicalState(altitude = new_altitude,
+                             velocity = new_velocity)
 
-def update_burn():
-    # line 420
-    q = delta_t * k / m
-    j = (v +
-         g * delta_t +
-         z * (-q - q*q/2 - q**3/3 - q**4/4 - q**5/5))
-    i = (a -
-         g * delta_t * delta_t/2 -
-         v * delta_t +
-         z * delta_t * (q / 2 +
-                        q ** 2 / 6 +
-                        q ** 3 / 12 +
-                        q ** 4 / 20 +
-                        q ** 5 / 30))
+    def make_state_display_string(self, sim_clock):
+        seconds = sim_clock.elapsed_time
+        miles = int(self.a)
+        feet = int(5280 * (self.a - miles))
+        velocity = int(3600 * self.v)
+        fuel = int(self.remaining_fuel())
+        burn_rate = " ? "
 
-    return q,j,i
+        return format_line_for_report(seconds, miles, feet, velocity, fuel, burn_rate, False)
+
+    def prompt_for_burn(self, sim_clock):
+        # line 150
+        PROMPT = True
+
+        msg = self.make_state_display_string(sim_clock)
+        if PROMPT:
+            self.fuel_per_second = float(input(msg))
+        else:
+            print(msg)
+            self.fuel_per_second = 0.0
+        sim_clock.time_until_next_prompt = 10
+    
+
+class SimulationClock:
+    def __init__(self, elapsed_time, time_until_next_prompt):
+        self.elapsed_time = elapsed_time
+        self.time_until_next_prompt = time_until_next_prompt
+
+    def time_for_prompt(self):
+        return self.time_until_next_prompt < 1e-3
+
+    def advance(self, delta_t):
+        self.elapsed_time += delta_t
+        self.time_until_next_prompt -= delta_t
+        
+
+def process_final_tick(delta_t, sim_clock, capsule):
+    # When we extrapolated our position based on our velocity
+    # and delta_t, we overshot the surface. For better
+    # accuracy, we will back up and do shorter time advances.
+            
+    # line 340
+    while True:
+        if delta_t < 5e-3:
+            show_landing(sim_clock, capsule)
+            return
+        #line 35
+        average_vel = (capsule.v +
+                       math.sqrt(capsule.v **2  +
+                                 2 * capsule.a * (capsule.g -
+                                                  capsule.z *
+                                                  capsule.fuel_per_second / capsule.m))) / 2
+        delta_t = capsule.a / average_vel
+        new_state = capsule.predict_motion(delta_t)
+        capsule.update_state(sim_clock, delta_t, new_state)
+
+def handle_flyaway(capsule):
+    """
+    The user has started flying away from the moon. Since this is a
+    lunar LANDING simulation, we wait until the capsule's velocity is
+    positive (downward) before prompting for more input.
+    
+    Returns True if landed, False if simulation should continue.
+    """
+    
+    while True:
+        # line 370
+        w = (1 - capsule.m * capsule.g / (capsule.z * capsule.fuel_per_second)) / 2
+        delta_t = (capsule.m * capsule.v /
+                   (capsule.z * capsule.fuel_per_second *
+                    math.sqrt(w**2 + capsule.v / capsule.z))) + 0.05
+                
+        new_state = capsule.predict_motion(delta_t)
+
+        # line 380
+        if new_state.altitude <= 0:
+            # have landed
+            return True
+
+        # line 390
+        capsule.update_state(sim_clock, delta_t, new_state)
+
+        if ((new_state.velocity > 0) or (capsule.v <= 0)):
+            # return to normal sim
+            return False
+
+
+
+    
 
 def end_sim():
     print()
     print()
     print()
     print("TRY AGAIN??")
+    print()
+    print()
+    print()
 
 
-def prompt_for_burn():
-    # line 150
-    print("{l}\t{a}\t{int(5280*(a-int(a)))}\t{3600 * v}\t{m-n}")
-    k = input()
-
 def run_simulation():
     print()
-    print("SEC\tMI + FT\tMPH\tLB FUEL\tBURN RATE")
-    print()
-    
-    elapsed_time = 0
-    a = 120
-    v = 1 
-    m = 33000 # mass of capsule with fuel
-    n = 16500 # mass of capsule without fuel
-    g = 1e-3
-    z = 1.8
+    print(format_line_for_report("SEC",
+                                 "MI",
+                                 "FT",
+                                 "MPH",
+                                 "LB FUEL",
+                                 "BURN RATE",
+                                 True))
 
-    k = prompt_for_burn()
-    time_to_prompt = 10
+    sim_clock = SimulationClock(0, 10)
+    capsule = Capsule()
+
+    capsule.prompt_for_burn(sim_clock)
 
     while True:
         # line 160
-        if M-N < 1e-3:
-            # line 240
-            print(f"FUEL OUT AT {elapsed_time} SECONDS")
-            delta_t = (-v + math.sqrt(v*v + 2*a*g)) / g
-            v += g * delta_t
-            elapsed_time += delta_t
-            show_landing(elapsed_time, v)
+        if capsule.is_out_of_fuel():
+            show_out_of_fuel(sim_clock, capsule)
             return
 
-        if t < 1e-3:
-            k = prompt_for_burn()
+        # line 170
+        if sim_clock.time_for_prompt():
+            capsule.prompt_for_burn(sim_clock)
             continue
 
         # line 180
-        delta_t = time_to_prompt
-        if m < n + delta_t * k:
-            delta_t = (m-n) / k
-            
-        # line 200
-        q,j,i = update_burn()
+        # clock advance is the shorter of the time to the next prompt,
+        # or when we run out of fuel.
+        if capsule.fuel_per_second > 0:
+            delta_t = min(sim_clock.time_until_next_prompt,
+                          capsule.fuel_time_remaining())
+        else:
+            delta_t = sim_clock.time_until_next_prompt
 
-        if i <= 0:
-            # line 340
-            while True:
-                if delta_t < 5e-3:
-                    show_landing(elapsed_time, v)
-                #line 350
-                d = v + math.sqrt(v*v + 2*a*(g-z*k/m))
-                delta_t = 2 * a / d
-                update_burn()
-                update_physics()
+        # line 200
+        new_state = capsule.predict_motion(delta_t)
+
+        if new_state.altitude <= 0:
+            process_final_tick(delta_t, sim_clock, capsule)
+            return
+
+        # line 210
+        if capsule.v > 0 and new_state.velocity < 0:
+            # moving away from the moon
+
+            landed = handle_flyaway(capsule)
+            if landed:
+                process_final_tick(delta_t, sim_clock, capsule)
+                return
 
         else:
-            # line 210
-            if ((v > 0) and (j < 0)):
-                GOTO 370
             # line 230
-            update_physics()
+            capsule.update_state(sim_clock, delta_t, new_state)
 
 
 
@@ -166,41 +363,76 @@ def main():
     while True:
         print_intro()
         run_simulation()
+
+if __name__ == "__main__":
+    main()
         
 
 """
+10 PRINT TAB(33);"LUNAR"
+20 PRINT TAB(l5);"CREATIVE COMPUTING MORRISTOWN, NEW JERSEY" 
+25 PRINT:PRINT:PRINT
+30 PRINT "THIS IS A COMPUTER SIMULATION OF AN APOLLO LUNAR" 
+40 PRINT "LANDING CAPSULE.": PRINT: PRINT
+50 PRINT "THE ON-BOARD COMPUTER HAS FAILED (IT WAS MADE BY" 
+60 PRINT "XEROX) SO YOU HAVE TO LAND THE CAPSULE MANUALLY."
+70 PRINT: PRINT "SET BURN RATE OF RETRO ROCKETS TO ANY VALUE BETWEEN" 
+80 PRINT "0 (FREE FALL) AND 200 (MAXIMUM BURN) POUNDS PER SECOND." 
+90 PRINT "SET NEW BURN RATE EVERY 10 SECONDS.": PRINT 
+100 PRINT "CAPSULE WEIGHT 32,500 LBS; FUEL WEIGHT 16,500 LBS."
+110 PRINT: PRINT: PRINT: PRINT "GOOD LUCK"
 120 L=0
 130 PRINT: PRINT "SEC","MI + FT","MPH","LB FUEL","BURN RATE":PRINT 
 140 A=120:V=1:M=33000:N=16500:G=1E-03:Z=1.8
+
+149 REM DWL capsule.prompt_for_burn
 150 PRINT L,INT(A);INT(5280*(A-INT(A))),3600*V,M-N,:INPUT K:T=10 
+
+159 REM main loop
 160 IF M-N<1E-03 THEN 240
 170 IF T<1E-03 THEN 150
 180 S=T: IF M>=N+S*K THEN 200
 190 S=(M-N)/K
-200 GOSUB 420: IF I<=O THEN 340
+200 GOSUB 420: IF I<=0 THEN 340
 210 IF V<=0 THEN 230
 220 IF J<0 THEN 370
 230 GOSUB 330: GOTO 160
+
+239 REM DWL show_out_of_fuel
 240 PRINT "FUEL OUT AT";L;"SECONDS":S=(-V+SQR(V*V+2*A*G))/G
 250 V=V+G*S: L=L+S
+
+259 REM DWL show_landing
 260 W=3600*V: PRINT "ON MOON AT";L;"SECONDS - IMPACT VELOCITY";W;"MPH" 
 274 IF W<=1.2 THEN PRINT "PERFECT LANDING!": GOTO 440 
-280 IF W<=10 THEN PRINT "GOOD LANDING (COULD RE BETTER)":GOTO 440 
+280 IF W<=10 THEN PRINT "GOOD LANDING (COULD BE BETTER)":GOTO 440 
 282 IF W>60 THEN 300
 284 PRINT "CRAFT DAMAGE... YOU'RE STRANDED HERE UNTIL A RESCUE" 
 286 PRINT "PARTY ARRIVES. HOPE YOU HAVE ENOUGH OXYGEN!" 
 288 GOTO 440
-300 PRINT "SORRY THERE NERE NO SURVIVORS. YOU BLOW IT!"
+300 PRINT "SORRY THERE WERE NO SURVIVORS. YOU BLEW IT!"
 310 PRINT "IN FACT, YOU BLASTED A NEW LUNAR CRATER";W*.227;"FEET DEEP!"
 320 GOTO 440
+
+329 REM DWL capsule.update_state
 330 L=L+S: T=T-S: M=M-S*K: A=I: V=J: RETURN
+
+339 REM DWL process_final_tick
 340 IF S<5E-03 THEN 260
 350 D=V+SQR(V*V+2*A*(G-Z*K/M)):S=2*A/D
 360 GOSUB 420: GOSUB 330: GOTO 340
+
+369 REM DWL handle_flyaway
 370 W=(1-M*G/(Z*K))/2: S=M*V/(Z*K*(W+SQR(W*W+V/Z)))+.05:GOSUB 420
 380 IF I<=0 THEN 340
 390 GOSUB 330: IF J>0 THEN 160
 400 IF V>0 THEN 370
 410 GOTO 160
 
+419 REM DWL capsule.predict_motion
+420 Q=S*K/M: J=V+G*S+Z*(-Q-Q*Q/2-Q^3/3-Q^4/4-Q^5/5)
+430 I=A-G*S*S/2-V*S+Z*S*(Q/2+Q^2/6+Q^3/12+Q^4/20+Q^5/30):RETURN
+
+439 REM DWL end_sim
+440 PRINT:PRINT:PRINT:PRINT "TRY AGAIN??": GOTO 70
 """

From 92ba86f67587c3417ab6c0ff3c7474e89392ca2d Mon Sep 17 00:00:00 2001
From: Dave LeCompte <tsmaster@gmail.com>
Date: Sat, 6 Mar 2021 14:45:29 -0800
Subject: [PATCH 3/3] more work on porting LUNAR to python

I have yet to beat this game, so I haven't fully tested it.
---
 59 Lunar LEM Rocket/python/lunar.py | 248 ++++++++++------------------
 1 file changed, 85 insertions(+), 163 deletions(-)

diff --git a/59 Lunar LEM Rocket/python/lunar.py b/59 Lunar LEM Rocket/python/lunar.py
index 93a73082..b55fc6f2 100644
--- a/59 Lunar LEM Rocket/python/lunar.py	
+++ b/59 Lunar LEM Rocket/python/lunar.py	
@@ -33,7 +33,8 @@ FUEL_RIGHT = FUEL_LEFT + FUEL_WIDTH
 BURN_LEFT = FUEL_RIGHT + COLUMN_WIDTH
 BURN_RIGHT = BURN_LEFT + BURN_WIDTH
 
-PhysicalState = collections.namedtuple('PhysicalState', ['velocity', 'altitude'])
+PhysicalState = collections.namedtuple("PhysicalState", ["velocity", "altitude"])
+
 
 def print_centered(msg):
     spaces = " " * ((PAGE_WIDTH - len(msg)) // 2)
@@ -47,9 +48,10 @@ def print_header(title):
     print()
     print()
 
+
 def add_rjust(line, s, pos):
     # adds a new field to a line right justified to end at pos
-    
+
     s = str(s)
     slen = len(s)
     if len(line) + slen > pos:
@@ -60,9 +62,10 @@ def add_rjust(line, s, pos):
         line = line + spaces
     return line + s
 
+
 def add_ljust(line, s, pos):
     # adds a new field to a line left justified starting at pos
-    
+
     s = str(s)
     slen = len(s)
     if len(line) > pos:
@@ -75,7 +78,7 @@ def add_ljust(line, s, pos):
 
 def print_instructions():
     # Somebody had a bad experience with Xerox.
-    
+
     print("THIS IS A COMPUTER SIMULATION OF AN APOLLO LUNAR")
     print("LANDING CAPSULE.")
     print()
@@ -84,6 +87,7 @@ def print_instructions():
     print("XEROX) SO YOU HAVE TO LAND THE CAPSULE MANUALLY.")
     print()
 
+
 def print_intro():
     print("SET BURN RATE OF RETRO ROCKETS TO ANY VALUE BETWEEN")
     print("0 (FREE FALL) AND 200 (MAXIMUM BURN) POUNDS PER SECOND.")
@@ -96,9 +100,12 @@ def print_intro():
     print("GOOD LUCK")
     print()
 
+
 def show_landing(sim_clock, capsule):
     w = 3600 * capsule.v
-    print(f"ON MOON AT {sim_clock.elapsed_time} SECONDS - IMPACT VELOCITY {w} MPH")
+    print(
+        f"ON MOON AT {sim_clock.elapsed_time:.2f} SECONDS - IMPACT VELOCITY {w:.2f} MPH"
+    )
     if w < 1.2:
         print("PERFECT LANDING!")
     elif w < 10:
@@ -108,19 +115,20 @@ def show_landing(sim_clock, capsule):
         print("PARTY ARRIVES. HOPE YOU HAVE ENOUGH OXYGEN!")
     else:
         print("SORRY THERE WERE NO SURVIVORS. YOU BLEW IT!")
-        print(f"IN FACT, YOU BLASTED A NEW LUNAR CRATER {w*.227:.4f} FEET DEEP!")
+        print(f"IN FACT, YOU BLASTED A NEW LUNAR CRATER {w*.227:.2f} FEET DEEP!")
     end_sim()
 
 
 def show_out_of_fuel(sim_clock, capsule):
-    # line 240
     print(f"FUEL OUT AT {sim_clock.elapsed_time} SECONDS")
-    delta_t = (-capsule.v + math.sqrt(capsule.v ** 2 + 2 *
-                                      capsule.a * capsule.g)) / capsule.g
+    delta_t = (
+        -capsule.v + math.sqrt(capsule.v ** 2 + 2 * capsule.a * capsule.g)
+    ) / capsule.g
     capsule.v += capsule.g * delta_t
     sim_clock.advance(delta_t)
     show_landing(sim_clock, capsule)
 
+
 def format_line_for_report(t, miles, feet, velocity, fuel, burn_rate, is_header):
     line = add_rjust("", t, SECONDS_RIGHT)
     line = add_rjust(line, miles, ALT_MI_RIGHT)
@@ -133,16 +141,19 @@ def format_line_for_report(t, miles, feet, velocity, fuel, burn_rate, is_header)
         line = add_ljust(line, burn_rate, BURN_LEFT)
     return line
 
+
 class Capsule:
-    def __init__(self,
-                 altitude = 120,
-                 velocity = 1,
-                 mass_with_fuel = 33000,
-                 mass_without_fuel = 16500,
-                 g = 1e-3,
-                 z = 1.8):
-        self.a = altitude # in miles above the surface
-        self.v = velocity # downward
+    def __init__(
+        self,
+        altitude=120,
+        velocity=1,
+        mass_with_fuel=33000,
+        mass_without_fuel=16500,
+        g=1e-3,
+        z=1.8,
+    ):
+        self.a = altitude  # in miles above the surface
+        self.v = velocity  # downward
         self.m = mass_with_fuel
         self.n = mass_without_fuel
         self.g = g
@@ -156,7 +167,6 @@ class Capsule:
         return self.remaining_fuel() < 1e-3
 
     def update_state(self, sim_clock, delta_t, new_state):
-        # line 330
         sim_clock.advance(delta_t)
         self.m = self.m - delta_t * self.fuel_per_second
         self.a = new_state.altitude
@@ -164,37 +174,32 @@ class Capsule:
 
     def fuel_time_remaining(self):
         # extrapolates out how many seconds we have at the current fuel burn rate
-        assert(self.fuel_per_second > 0)
+        assert self.fuel_per_second > 0
         return self.remaining_fuel() / self.fuel_per_second
 
     def predict_motion(self, delta_t):
         # Perform an Euler's Method numerical integration of the equations of motion.
 
-        # line 420
         q = delta_t * self.fuel_per_second / self.m
 
         # new velocity
-        new_velocity = (self.v +
-                        self.g * delta_t +
-                        self.z * (-q -
-                                  q ** 2 / 2 -
-                                  q ** 3 / 3 -
-                                  q ** 4 / 4 -
-                                  q ** 5 / 5))
+        new_velocity = (
+            self.v
+            + self.g * delta_t
+            + self.z * (-q - q ** 2 / 2 - q ** 3 / 3 - q ** 4 / 4 - q ** 5 / 5)
+        )
 
         # new altitude
-        new_altitude = (self.a -
-                        self.g * delta_t ** 2 / 2 -
-                        self.v * delta_t +
-                        self.z * delta_t * (q / 2 +
-                                            q ** 2 / 6 +
-                                            q ** 3 / 12 +
-                                            q ** 4 / 20 +
-                                            q ** 5 / 30))
+        new_altitude = (
+            self.a
+            - self.g * delta_t ** 2 / 2
+            - self.v * delta_t
+            + self.z
+            * delta_t
+            * (q / 2 + q ** 2 / 6 + q ** 3 / 12 + q ** 4 / 20 + q ** 5 / 30)
+        )
 
-        
-        return PhysicalState(altitude = new_altitude,
-                             velocity = new_velocity)
+        return PhysicalState(altitude=new_altitude, velocity=new_velocity)
 
     def make_state_display_string(self, sim_clock):
         seconds = sim_clock.elapsed_time
@@ -204,20 +209,16 @@ class Capsule:
         fuel = int(self.remaining_fuel())
         burn_rate = " ? "
 
-        return format_line_for_report(seconds, miles, feet, velocity, fuel, burn_rate, False)
+        return format_line_for_report(
+            seconds, miles, feet, velocity, fuel, burn_rate, False
+        )
 
     def prompt_for_burn(self, sim_clock):
-        # line 150
-        PROMPT = True
-
         msg = self.make_state_display_string(sim_clock)
-        if PROMPT:
-            self.fuel_per_second = float(input(msg))
-        else:
-            print(msg)
-            self.fuel_per_second = 0.0
+
+        self.fuel_per_second = float(input(msg))
         sim_clock.time_until_next_prompt = 10
-    
+
 
 class SimulationClock:
     def __init__(self, elapsed_time, time_until_next_prompt):
@@ -230,62 +231,66 @@ class SimulationClock:
     def advance(self, delta_t):
         self.elapsed_time += delta_t
         self.time_until_next_prompt -= delta_t
-        
+
 
 def process_final_tick(delta_t, sim_clock, capsule):
     # When we extrapolated our position based on our velocity
     # and delta_t, we overshot the surface. For better
     # accuracy, we will back up and do shorter time advances.
-            
-    # line 340
+
     while True:
         if delta_t < 5e-3:
             show_landing(sim_clock, capsule)
             return
-        #line 35
-        average_vel = (capsule.v +
-                       math.sqrt(capsule.v **2  +
-                                 2 * capsule.a * (capsule.g -
-                                                  capsule.z *
-                                                  capsule.fuel_per_second / capsule.m))) / 2
+        # line 35
+        average_vel = (
+            capsule.v
+            + math.sqrt(
+                capsule.v ** 2
+                + 2
+                * capsule.a
+                * (capsule.g - capsule.z * capsule.fuel_per_second / capsule.m)
+            )
+        ) / 2
         delta_t = capsule.a / average_vel
         new_state = capsule.predict_motion(delta_t)
         capsule.update_state(sim_clock, delta_t, new_state)
 
-def handle_flyaway(capsule):
+
+def handle_flyaway(sim_clock, capsule):
     """
     The user has started flying away from the moon. Since this is a
     lunar LANDING simulation, we wait until the capsule's velocity is
     positive (downward) before prompting for more input.
-    
+
     Returns True if landed, False if simulation should continue.
     """
-    
+
     while True:
-        # line 370
         w = (1 - capsule.m * capsule.g / (capsule.z * capsule.fuel_per_second)) / 2
-        delta_t = (capsule.m * capsule.v /
-                   (capsule.z * capsule.fuel_per_second *
-                    math.sqrt(w**2 + capsule.v / capsule.z))) + 0.05
-                
+        delta_t = (
+            capsule.m
+            * capsule.v
+            / (
+                capsule.z
+                * capsule.fuel_per_second
+                * math.sqrt(w ** 2 + capsule.v / capsule.z)
+            )
+        ) + 0.05
+
         new_state = capsule.predict_motion(delta_t)
 
-        # line 380
         if new_state.altitude <= 0:
             # have landed
             return True
 
-        # line 390
         capsule.update_state(sim_clock, delta_t, new_state)
 
-        if ((new_state.velocity > 0) or (capsule.v <= 0)):
+        if (new_state.velocity > 0) or (capsule.v <= 0):
             # return to normal sim
             return False
 
 
-
-    
-
 def end_sim():
     print()
     print()
@@ -298,13 +303,9 @@ def end_sim():
 
 def run_simulation():
     print()
-    print(format_line_for_report("SEC",
-                                 "MI",
-                                 "FT",
-                                 "MPH",
-                                 "LB FUEL",
-                                 "BURN RATE",
-                                 True))
+    print(
+        format_line_for_report("SEC", "MI", "FT", "MPH", "LB FUEL", "BURN RATE", True)
+    )
 
     sim_clock = SimulationClock(0, 10)
     capsule = Capsule()
@@ -312,51 +313,41 @@ def run_simulation():
     capsule.prompt_for_burn(sim_clock)
 
     while True:
-        # line 160
         if capsule.is_out_of_fuel():
             show_out_of_fuel(sim_clock, capsule)
             return
 
-        # line 170
         if sim_clock.time_for_prompt():
             capsule.prompt_for_burn(sim_clock)
             continue
 
-        # line 180
         # clock advance is the shorter of the time to the next prompt,
         # or when we run out of fuel.
         if capsule.fuel_per_second > 0:
-            delta_t = min(sim_clock.time_until_next_prompt,
-                          capsule.fuel_time_remaining())
+            delta_t = min(
+                sim_clock.time_until_next_prompt, capsule.fuel_time_remaining()
+            )
         else:
             delta_t = sim_clock.time_until_next_prompt
 
-        # line 200
         new_state = capsule.predict_motion(delta_t)
 
         if new_state.altitude <= 0:
             process_final_tick(delta_t, sim_clock, capsule)
             return
 
-        # line 210
         if capsule.v > 0 and new_state.velocity < 0:
             # moving away from the moon
 
-            landed = handle_flyaway(capsule)
+            landed = handle_flyaway(sim_clock, capsule)
             if landed:
                 process_final_tick(delta_t, sim_clock, capsule)
                 return
 
         else:
-            # line 230
             capsule.update_state(sim_clock, delta_t, new_state)
 
 
-
-        
-        
-
-
 def main():
     print_header("LUNAR")
     print_instructions()
@@ -364,75 +355,6 @@ def main():
         print_intro()
         run_simulation()
 
+
 if __name__ == "__main__":
     main()
-        
-
-"""
-10 PRINT TAB(33);"LUNAR"
-20 PRINT TAB(l5);"CREATIVE COMPUTING MORRISTOWN, NEW JERSEY" 
-25 PRINT:PRINT:PRINT
-30 PRINT "THIS IS A COMPUTER SIMULATION OF AN APOLLO LUNAR" 
-40 PRINT "LANDING CAPSULE.": PRINT: PRINT
-50 PRINT "THE ON-BOARD COMPUTER HAS FAILED (IT WAS MADE BY" 
-60 PRINT "XEROX) SO YOU HAVE TO LAND THE CAPSULE MANUALLY."
-70 PRINT: PRINT "SET BURN RATE OF RETRO ROCKETS TO ANY VALUE BETWEEN" 
-80 PRINT "0 (FREE FALL) AND 200 (MAXIMUM BURN) POUNDS PER SECOND." 
-90 PRINT "SET NEW BURN RATE EVERY 10 SECONDS.": PRINT 
-100 PRINT "CAPSULE WEIGHT 32,500 LBS; FUEL WEIGHT 16,500 LBS."
-110 PRINT: PRINT: PRINT: PRINT "GOOD LUCK"
-120 L=0
-130 PRINT: PRINT "SEC","MI + FT","MPH","LB FUEL","BURN RATE":PRINT 
-140 A=120:V=1:M=33000:N=16500:G=1E-03:Z=1.8
-
-149 REM DWL capsule.prompt_for_burn
-150 PRINT L,INT(A);INT(5280*(A-INT(A))),3600*V,M-N,:INPUT K:T=10 
-
-159 REM main loop
-160 IF M-N<1E-03 THEN 240
-170 IF T<1E-03 THEN 150
-180 S=T: IF M>=N+S*K THEN 200
-190 S=(M-N)/K
-200 GOSUB 420: IF I<=0 THEN 340
-210 IF V<=0 THEN 230
-220 IF J<0 THEN 370
-230 GOSUB 330: GOTO 160
-
-239 REM DWL show_out_of_fuel
-240 PRINT "FUEL OUT AT";L;"SECONDS":S=(-V+SQR(V*V+2*A*G))/G
-250 V=V+G*S: L=L+S
-
-259 REM DWL show_landing
-260 W=3600*V: PRINT "ON MOON AT";L;"SECONDS - IMPACT VELOCITY";W;"MPH" 
-274 IF W<=1.2 THEN PRINT "PERFECT LANDING!": GOTO 440 
-280 IF W<=10 THEN PRINT "GOOD LANDING (COULD BE BETTER)":GOTO 440 
-282 IF W>60 THEN 300
-284 PRINT "CRAFT DAMAGE... YOU'RE STRANDED HERE UNTIL A RESCUE" 
-286 PRINT "PARTY ARRIVES. HOPE YOU HAVE ENOUGH OXYGEN!" 
-288 GOTO 440
-300 PRINT "SORRY THERE WERE NO SURVIVORS. YOU BLEW IT!"
-310 PRINT "IN FACT, YOU BLASTED A NEW LUNAR CRATER";W*.227;"FEET DEEP!"
-320 GOTO 440
-
-329 REM DWL capsule.update_state
-330 L=L+S: T=T-S: M=M-S*K: A=I: V=J: RETURN
-
-339 REM DWL process_final_tick
-340 IF S<5E-03 THEN 260
-350 D=V+SQR(V*V+2*A*(G-Z*K/M)):S=2*A/D
-360 GOSUB 420: GOSUB 330: GOTO 340
-
-369 REM DWL handle_flyaway
-370 W=(1-M*G/(Z*K))/2: S=M*V/(Z*K*(W+SQR(W*W+V/Z)))+.05:GOSUB 420
-380 IF I<=0 THEN 340
-390 GOSUB 330: IF J>0 THEN 160
-400 IF V>0 THEN 370
-410 GOTO 160
-
-419 REM DWL capsule.predict_motion
-420 Q=S*K/M: J=V+G*S+Z*(-Q-Q*Q/2-Q^3/3-Q^4/4-Q^5/5)
-430 I=A-G*S*S/2-V*S+Z*S*(Q/2+Q^2/6+Q^3/12+Q^4/20+Q^5/30):RETURN
-
-439 REM DWL end_sim
-440 PRINT:PRINT:PRINT:PRINT "TRY AGAIN??": GOTO 70
-"""