diff --git a/interactions.py b/interactions.py
index 4331426..9fd3e86 100644
--- a/interactions.py
+++ b/interactions.py
@@ -10,7 +10,7 @@ import phue, pygame, colorsys
 viewsize = 600
 shrink = 0.9
 vertices = [(viewsize*(1 + shrink*x)/2, viewsize*(1 + shrink*y)/2) for x, y in
-  [(0, 0)] + [(cos(-n*pi/5), sin(-n*pi/5)) for n in range(10)] + [(0, 0)]
+  [(0, 0)] + [(sin(n*pi/5), -cos(n*pi/5)) for n in range(10)] + [(0, 0)]
 ]
 
 # edges as vertex pairs. FireStar will rest on vertices 6 (A), 5 (B), 7 (C)
@@ -18,7 +18,7 @@ vertex_adj = [
   (0, 1), (0, 3), (0, 5), (0, 7), (0, 9),
   (2, 8), (2, 6), (6, 10), (10, 4), (4, 8),
   (2, 9), (2, 11), (2, 5),
-  (4, 1), (4, 9), (4, 7),
+  (4, 1), (4, 11), (4, 7),
   (6, 3), (6, 11), (6, 9),
   (8, 5), (8, 11), (8, 1),
   (10, 7), (10, 11), (10, 3),
@@ -72,7 +72,10 @@ lasthue = 65535
 fullbright = 254
 fullsat = 254
 
-# --- control methods
+# --- control methods and diagnostics
+
+updates = 0
+new_updates = 0
 
 def set_light_hsv(e, color, hit_bridge):
   command = {
@@ -80,39 +83,86 @@ def set_light_hsv(e, color, hit_bridge):
     'bri' : int(color[2]*fullbright),
     'sat' : int(color[1]*fullsat)
   }
-  if hit_bridge and b != None:
-    b.set_light(edges[e].light_id, command)
+  if hit_bridge:
+    if b != None:
+      b.set_light(edges[e].light_id, command)
+    global new_updates
+    new_updates += 1
   rgb_color = tuple(255*c for c in colorsys.hsv_to_rgb(*color))
   pygame.draw.aaline(screen, rgb_color, vertices[vertex_adj[e][0]], vertices[vertex_adj[e][1]])
 
+# === messages and mode selection ===
+
+mode = 0
+
+# data labels
+updates_label = font.render('updates', True, (255, 255, 255))
+energy_label = font.render('energy', True, (255, 255, 255))
+position_label = [
+  font.render('temp[0]', True, (255, 255, 255)),
+  font.render('charge[0]', True, (255, 255, 255))
+]
+
+# instructions
+mode_inds = [
+  [
+    font.render('[d] heat', True, (255, 255, 255)),
+    font.render('[f] wave', True, (150, 150, 150))
+  ],
+  [
+    font.render('[d] heat', True, (150, 150, 150)),
+    font.render('[f] wave', True, (255, 255, 255))
+  ]
+]
+bop_instr = [
+  font.render('press [j] to bop', True, (255, 255, 255)),
+  font.render('press [j] or [k] to bop', True, (255, 255, 255))
+]
+drain_instr = font.render('hold [space] to drain', True, (255, 255, 255))
+
+# set up background
+background = pygame.Surface(screen.get_size()).convert()
+background.fill((32, 32, 32))
+background.blit(drain_instr, (340, 60 + viewsize))
+
 # === interaction parameters ===
 
-frame_rate = 2
+# these frame rate and threshold settings are untested, but the exponential
+# moving average update frequency suggests they should be just barely in bounds
+frame_rate = 10
+ema_weight = 2/(frame_rate+1)
 
 inductance = 0.001
 
-therm_conduct = 0.001
+therm_conduct = 0.01
 
 drain = False
 drain_rate = 0.1
 
 # === phase space ===
 
+# heat equation
+temp = 30*[0]
+new_temp = 30*[0]
+
+# wave equation
 charge = 12*[0]
 current = 30*[0]
 
-last_litness = 30*[float("inf")]
-change_threshold = 0.05
+litness = 30*[float("inf")]
+change_threshold = 0.15
 
 # === main loop ===
 
 def heat_evolution():
   for e, f in cyc_edge_adj:
-    flow = therm_conduct*(current[e] - current[f])
-    current[e] -= flow
-    current[f] += flow
+    flow = therm_conduct*(temp[e] - temp[f])
+    new_temp[e] -= flow
+    new_temp[f] += flow
+  for e in range(30):
     if drain:
-      current[v] *= 1 - drain_rate
+      new_temp[e] *= 1 - drain_rate
+    temp[e] = max(new_temp[e], 0)
 
 def wave_evolution():
   # use verlet integration, first updating the currents and then using the new
@@ -128,66 +178,115 @@ def wave_evolution():
     for v in range(12):
       charge[v] *= 1 - drain_rate
 
+def set_heat_light(e, i):
+  new_litness = 1 - exp(-2*i)
+  if abs(new_litness - litness[e]) > change_threshold:
+    hit_bridge = True
+    litness[e] = new_litness
+  else:
+    hit_bridge = False
+  set_light_hsv(e, (0.167*litness[e], 1 - 0.5*litness[e]*litness[e], litness[e]), hit_bridge)
+
 def set_wave_light(e, i):
-  litness = 1 - exp(-2*i*i)
-  hit_bridge = abs(litness - last_litness[e]) > change_threshold
-  set_light_hsv(e, (0.45 + litness*0.25, 1 - 0.5*litness*litness, litness), hit_bridge)
-  if hit_bridge:
-    last_litness[e] = litness
+  new_litness = 1 - exp(-2*i*i)
+  if abs(new_litness - litness[e]) > change_threshold:
+    hit_bridge = True
+    litness[e] = new_litness
+  else:
+    hit_bridge = False
+  set_light_hsv(e, (0.45 + litness[e]*0.25, 1 - 0.5*litness[e]*litness[e], litness[e]), hit_bridge)
+
+def handle_heat_events():
+  global drain, mode
+  for event in pygame.event.get():
+    if event.type == pygame.KEYDOWN:
+      if event.key == pygame.K_j:
+        new_temp[0] += 10
+      elif event.key == pygame.K_SPACE:
+        drain = True
+      elif event.key == pygame.K_f:
+        mode = 1
+    elif event.type == pygame.KEYUP:
+      if event.key == pygame.K_SPACE:
+        drain = False
+    elif event.type == pygame.QUIT:
+      quit()
+
+def handle_wave_events():
+  global drain, mode
+  for event in pygame.event.get():
+    if event.type == pygame.KEYDOWN:
+      if event.key == pygame.K_j:
+        charge[0] += 100
+        charge[11] -= 100
+      elif event.key == pygame.K_k:
+        charge[5] += 100
+        charge[7] -= 100
+      elif event.key == pygame.K_SPACE:
+        drain = True
+      elif event.key == pygame.K_d:
+        mode = 0
+    elif event.type == pygame.KEYUP:
+      if event.key == pygame.K_SPACE:
+        drain = False
+    elif event.type == pygame.QUIT:
+      quit()
 
 def show_data(screen):
-  energy = 0.5*(sum(q*q for q in charge) + inductance*sum(i*i for i in current))
-  text = font.render('energy', True, (255, 255, 255))
-  screen.blit(text, (20, viewsize))
-  text = font.render(str(energy), True, (255, 255, 255))
-  screen.blit(text, (120, viewsize))
-  text = font.render('charge[0]', True, (255, 255, 255))
-  screen.blit(text, (20, 30 + viewsize))
-  text = font.render(str(charge[0]), True, (255, 255, 255))
-  screen.blit(text, (120, 30 + viewsize))
+  # light updates
+  global updates, new_updates
+  updates = ema_weight*new_updates + (1 - ema_weight)*updates
+  new_updates = 0
+  updates_value = font.render(str(frame_rate * updates), True, (255, 255, 255))
+  screen.blit(updates_label, (20, viewsize))
+  screen.blit(updates_value, (120, viewsize))
+  
+  # energy
+  if mode == 0:
+    energy = sum(temp)
+  elif mode == 1:
+    energy = 0.5*(sum(q*q for q in charge) + inductance*sum(i*i for i in current))
+  energy_value = font.render(str(energy), True, (255, 255, 255))
+  screen.blit(energy_label, (20, 30 + viewsize))
+  screen.blit(energy_value, (120, 30 + viewsize))
+  
+  # a position
+  ##position_value = None
+  if mode == 0:
+    position_value = font.render(str(temp[0]), True, (255, 255, 255))
+  elif mode == 1:
+    position_value = font.render(str(charge[0]), True, (255, 255, 255))
+  screen.blit(position_label[mode], (20, 60 + viewsize))
+  screen.blit(position_value, (120, 60 + viewsize))
+  
+  # instructions
+  screen.blit(mode_inds[mode][0], (340, viewsize))
+  screen.blit(mode_inds[mode][1], (420, viewsize))
+  screen.blit(bop_instr[mode], (340, 30 + viewsize))
 
 if __name__ == '__main__':
-  # set up background
-  background = pygame.Surface(screen.get_size()).convert()
-  background.fill((32, 32, 32))
-  text = font.render('press [j] or [k] to pluck', True, (255, 255, 255))
-  background.blit(text, (340, viewsize))
-  text = font.render('hold [space] to drain', True, (255, 255, 255))
-  background.blit(text, (340, 30 + viewsize))
-  
-  to_light = 0
   while True:
     # handle events
-    for event in pygame.event.get():
-      if event.type == pygame.KEYDOWN:
-        if event.key == pygame.K_j:
-          charge[0] += 100
-          charge[11] -= 100
-        elif event.key == pygame.K_k:
-          charge[5] += 100
-          charge[7] -= 100
-        elif event.key == pygame.K_SPACE:
-          drain = True
-        pygame.draw.aaline(screen, (255, 255, 255), (0, 0), (viewsize, viewsize))
-      elif event.type == pygame.KEYUP:
-        if event.key == pygame.K_SPACE:
-          drain = False
-      elif event.type == pygame.QUIT:
-        quit()
+    if mode == 0:
+      handle_heat_events()
+    elif mode == 1:
+      handle_wave_events()
     
     # clear screen
     screen.blit(background, (0, 0))
     
-    # show data
+    # show data and instructions
     show_data(screen)
     
-    # show state
-    for e in range(30):
-      set_wave_light(e, current[e])
-    
-    # evolve state
-    wave_evolution()
-    ##heat_evolution()
+    # show state and evolve state
+    if mode == 0:
+      for e in range(30):
+        set_heat_light(e, temp[e])
+      heat_evolution()
+    elif mode == 1:
+      for e in range(30):
+        set_wave_light(e, current[e])
+      wave_evolution()
     
     # step
     pygame.display.flip()