From 014df61e4f7b3a5a60a161f095f6ac92cb2881ce Mon Sep 17 00:00:00 2001
From: git-sandro <sandro-zimmermann@outlook.com>
Date: Fri, 5 Dec 2025 15:33:14 +0100
Subject: [PATCH] verkehrsimulation

---
 verkehrssimulation/verkehr.py    | 55 ++++++++++++++++++++++++++++++++
 verkehrssimulation/verkehr_sk.py | 21 ++----------
 2 files changed, 57 insertions(+), 19 deletions(-)
 create mode 100644 verkehrssimulation/verkehr.py

diff --git a/verkehrssimulation/verkehr.py b/verkehrssimulation/verkehr.py
new file mode 100644
index 0000000..b801d3b
--- /dev/null
+++ b/verkehrssimulation/verkehr.py
@@ -0,0 +1,55 @@
+#!/usr/bin/python
+
+import numpy as np
+import matplotlib.pyplot as plt
+
+GRIDSIZE = 300
+INIT_CELLS = int(GRIDSIZE*0.3)
+MAX_TIME = 300
+EMPTY_CELL = -1
+DALLY_LIMIT = 0.2
+
+
+# query distance between two cars
+def get_distance(grid, i):
+    dist = 0
+    while grid[(i+dist+1)%GRIDSIZE] == EMPTY_CELL and dist < 5:
+        dist = dist + 1
+    return dist
+
+# state transition t -> t + dt
+def update(grid_old, grid_new):
+    for i in range(GRIDSIZE):
+
+        if grid_old[i] != EMPTY_CELL:
+            v = np.min((grid_old[i]+1, 5))    # accelerate
+            dist = get_distance(grid_old, i)
+            if v > dist: v = dist             # break
+            p = np.random.random()
+            if p == DALLY_LIMIT: v = max(grid_old[i-1], 0)
+            grid_new[(i+v)%GRIDSIZE] = v      # move
+
+# allocate memory and initialise grids
+grid_old = np.full((GRIDSIZE), EMPTY_CELL, dtype=np.int32)
+grid_new = np.full((GRIDSIZE), EMPTY_CELL, dtype=np.int32)
+traffic = np.zeros((MAX_TIME, GRIDSIZE), dtype=np.int32)
+
+# set intial car positions and velocities
+for k in range(INIT_CELLS):
+    while True:
+        i = int(float(GRIDSIZE)*np.random.random())
+        if grid_old[i] == EMPTY_CELL:
+            grid_old[i] = int(float(6)*np.random.random())
+            break
+
+# run updates
+for t in range(MAX_TIME):
+    traffic[t,:] = grid_old[:]
+    update(grid_old, grid_new)
+    for i in range(GRIDSIZE):
+        grid_old[i] = grid_new[i]
+        grid_new[i] = EMPTY_CELL
+plt.xlabel('Cells')
+plt.ylabel('Timesteps')
+plt.imshow(traffic, cmap='Blues')
+plt.show()
diff --git a/verkehrssimulation/verkehr_sk.py b/verkehrssimulation/verkehr_sk.py
index d11676f..c6b79bd 100644
--- a/verkehrssimulation/verkehr_sk.py
+++ b/verkehrssimulation/verkehr_sk.py
@@ -9,12 +9,6 @@ INIT_CELLS = int(GRIDSIZE*0.1)
 MAX_TIME = 300
 EMPTY_CELL = -1
 
-def unit_distance(grid, v):
-    for i in range(1, v):
-        if grid[i] != -1:
-            return i
-    return -1
-
 # query distance between two cars
 def get_distance(grid, i):
     dist = 0
@@ -23,10 +17,7 @@ def get_distance(grid, i):
     Insert your code here
     """
 
-    print(i % 300)
-    quit()
-
-    for n in range(1, grid[i]+1):
+    for n in range(1, (grid[i]+1)&GRIDSIZE):
         if grid[i + n] != -1:
             return n
     return -1
@@ -40,15 +31,7 @@ def update(grid_old, grid_new):
         Insert your code here
         """
         if dist != -1:
-            if dist == 0:
-                grid_new[i] = 0
-            elif dist - grid_old[i] < 0:
-                grid_new[i] = dist - 1
-            else:
-                if grid_old[i] != 5:
-                    grid_new[i] += 1
-                else:
-                    grid_new[i] = grid_old[i]
+            print(dist)
 
 # allocate memory and initialise grids
 grid_old = np.full((GRIDSIZE), EMPTY_CELL, dtype=np.int32)