medium random location

random_location_3.py

def vis_random_location_process(num_pt, geo_df):
  """
  Generate num_pt random location coordinates .

  :param num_pt INT number of random location coordinates
  :param geo_df geopandas.geodataframe.GeoDataFrame contains geo data
  """
  polygon = geo_df["geometry"]
  
  # define boundaries
  bounds_all = polygon.bounds
  minx = min(bounds_all.minx)
  maxx = max(bounds_all.maxx)
  miny = min(bounds_all.miny)
  maxy = max(bounds_all.maxy)

  i = 0
  x_1 = []
  y_1 = []
  x_2 = []
  y_2 = []
  while i < num_pt:
    # generate random location coordinates
    x_t = np.random.uniform(minx, maxx)
    y_t = np.random.uniform(miny, maxy)
    x_1.append(x_t)
    y_1.append(y_t)
    # further check whether it is in the city area 
    for p in polygon:
      if Point(x_t, y_t).within(p):
        x_2.append(x_t)
        y_2.append(y_t)
        del x_1[-1]
        del y_1[-1]
        i = i + 1
        break

  rect1 = patches.Rectangle((minx, miny), maxx-minx, maxy-miny, linewidth=1, 
                           edgecolor='r', facecolor='none')
  rect2 = copy(rect1)
  rect3 = copy(rect1)
  rect4 = copy(rect1)
  
  ax1 = geo_df.plot()
  ax2 = geo_df.plot()
  ax3 = geo_df.plot()
  ax4 = geo_df.plot()
  ax1.add_patch(rect1)
  ax2.add_patch(rect2)
  ax3.add_patch(rect3)
  ax4.add_patch(rect4)
  ax2.plot(x_1, y_1, "ro")
  ax2.plot(x_2, y_2, "ro")
  ax3.plot(x_1, y_1, "bo")
  ax3.plot(x_2, y_2, "ro")
  ax4.plot(x_2, y_2, "ro")
  ax1.set_title("Step 1: Define boundaries")
  ax2.set_title("Step 2: Generate rondom locations")
  ax3.set_title("Step 3: Validate locations")
  ax4.set_title("Step 4: Remove invalid locations")
  plt.tight_layout()
  ax1.figure.savefig("step1.png", dpi=150)
  ax2.figure.savefig("step2.png", dpi=150)
  ax3.figure.savefig("step3.png", dpi=150)
  ax4.figure.savefig("step4.png", dpi=150)
  plt.show()
  
vis_random_location_process(30, düsseldorf_df)