diff --git a/Mapping/grid_map/grid_map.py b/Mapping/gaussian_grid_map/gaussian_grid_map.py
similarity index 100%
rename from Mapping/grid_map/grid_map.py
rename to Mapping/gaussian_grid_map/gaussian_grid_map.py
diff --git a/Mapping/raycasting_grid_map/raycasting_grid_map.py b/Mapping/raycasting_grid_map/raycasting_grid_map.py
new file mode 100644
index 00000000..154c8fc2
--- /dev/null
+++ b/Mapping/raycasting_grid_map/raycasting_grid_map.py
@@ -0,0 +1,162 @@
+"""
+
+2D grid map sample
+
+author: Atsushi Sakai (@Atsushi_twi)
+
+"""
+
+import math
+import numpy as np
+import matplotlib.pyplot as plt
+from scipy.stats import norm
+
+AREA_WIDTH = 10.0
+
+STD = 10.0  # standard diviation
+
+
+def generate_gaussian_grid_map(ox, oy, xyreso):
+
+    minx, miny, maxx, maxy, xw, yw = calc_grid_map_config(ox, oy, xyreso)
+
+    # calc each potential
+    pmap = [[0.0 for i in range(yw)] for i in range(xw)]
+
+    for ix in range(xw):
+        for iy in range(yw):
+
+            x = ix * xyreso + minx
+            y = iy * xyreso + miny
+
+            # Search minimum distance
+            mindis = float("inf")
+            for (iox, ioy) in zip(ox, oy):
+                d = math.sqrt((iox - x)**2 + (ioy - y)**2)
+                if mindis >= d:
+                    mindis = d
+
+            pdf = (1.0 - norm.cdf(mindis, 0.0, STD))
+            pmap[ix][iy] = pdf
+
+    draw_heatmap(pmap, minx, maxx, miny, maxy, xyreso)
+    plt.plot(ox, oy, "xr")
+    plt.plot(0.0, 0.0, "ob")
+
+
+def calc_grid_map_config(ox, oy, xyreso):
+    minx = round(min(ox) - AREA_WIDTH / 2.0)
+    miny = round(min(oy) - AREA_WIDTH / 2.0)
+    maxx = round(max(ox) + AREA_WIDTH / 2.0)
+    maxy = round(max(oy) + AREA_WIDTH / 2.0)
+    xw = int(round((maxx - minx) / xyreso))
+    yw = int(round((maxy - miny) / xyreso))
+
+    return minx, miny, maxx, maxy, xw, yw
+
+
+class precastDB:
+
+    def __init__(self):
+        self.px = 0.0
+        self.py = 0.0
+        self.d = 0.0
+        self.angle = 0.0
+        self.ix = 0
+        self.iy = 0
+
+    def __str__(self):
+        return str(self.px) + "," + str(self.py) + "," + str(self.d) + "," + str(self.angle)
+
+
+def precasting(minx, miny, xw, yw, xyreso, yawreso):
+
+    precast = [[] for i in range(round((math.pi * 2.0) / yawreso) + 1)]
+
+    for ix in range(xw):
+        for iy in range(yw):
+            px = ix * xyreso + minx
+            py = iy * xyreso + miny
+
+            d = math.sqrt(px**2 + py**2)
+            angle = math.atan2(py, px)
+            if angle < 0.0:
+                angle += math.pi * 2.0
+
+            angleid = math.floor(angle / yawreso)
+
+            pc = precastDB()
+
+            pc.px = px
+            pc.py = py
+            pc.d = d
+            pc.ix = ix
+            pc.iy = iy
+            pc.angle = angle
+
+            precast[angleid].append(pc)
+
+    return precast
+
+
+def generate_ray_casting_grid_map(ox, oy, xyreso):
+
+    minx, miny, maxx, maxy, xw, yw = calc_grid_map_config(ox, oy, xyreso)
+
+    pmap = [[0.0 for i in range(yw)] for i in range(xw)]
+
+    yawreso = math.radians(10.0)
+
+    precast = precasting(minx, miny, xw, yw, xyreso, yawreso)
+
+    for (x, y) in zip(ox, oy):
+
+        d = math.sqrt(x**2 + y**2)
+        angle = math.atan2(y, x)
+        if angle < 0.0:
+            angle += math.pi * 2.0
+
+        angleid = math.floor(angle / yawreso)
+
+        gridlist = precast[angleid]
+
+        ix = int(round((x - minx) / xyreso))
+        iy = int(round((y - miny) / xyreso))
+
+        for grid in gridlist:
+            if grid.d > (d):
+                pmap[grid.ix][grid.iy] = 0.5
+
+        pmap[ix][iy] = 1.0
+
+    draw_heatmap(pmap, minx, maxx, miny, maxy, xyreso)
+    plt.plot(ox, oy, "xr")
+    plt.plot(0.0, 0.0, "ob")
+
+
+def draw_heatmap(data, minx, maxx, miny, maxy, xyreso):
+    x, y = np.mgrid[slice(minx - xyreso / 2.0, maxx + xyreso / 2.0, xyreso),
+                    slice(miny - xyreso / 2.0, maxy + xyreso / 2.0, xyreso)]
+    plt.pcolor(x, y, data, vmax=1.0, cmap=plt.cm.Blues)
+    plt.axis("equal")
+
+
+def main():
+    print(__file__ + " start!!")
+
+    xyreso = 0.5
+
+    for i in range(5):
+        ox = (np.random.rand(4) - 0.5) * 10.0
+        oy = (np.random.rand(4) - 0.5) * 10.0
+        plt.cla()
+        generate_gaussian_grid_map(ox, oy, xyreso)
+        plt.pause(1.0)
+
+        plt.cla()
+        generate_ray_casting_grid_map(ox, oy, xyreso)
+        plt.pause(1.0)
+
+
+if __name__ == '__main__':
+    main()