diff --git a/draw_merged_sine_wave2.py b/draw_merged_sine_wave2.py
new file mode 100644
index 0000000..c0edb16
--- /dev/null
+++ b/draw_merged_sine_wave2.py
@@ -0,0 +1,76 @@
+import numpy as np
+from matplotlib import pyplot as plt
+
+
+def merge_different_amp():
+    f, phi = 5, 0
+    A = [1,2,3,4]
+    t = np.linspace(0.0, 2, 1000)
+
+    y = [A[i] * np.sin(2*np.pi*f*t) for i in range(len(A))]
+    sum_y = sum(y)
+
+    for i in range(len(y)):
+        plt.subplot(4,1,i+1)
+        plt.plot(t, y[i])
+        plt.ylim(-4,4)
+        plt.title("y="+str(A[i])+r"$\sin 10 \pi t$")
+
+    plt.tight_layout()
+    plt.show()
+
+    plt.plot(t, sum_y)
+    plt.title("sum of y")
+    plt.show()
+
+def merge_different_freq():
+    A, phi = 1, 0
+    f = [2,4,6,8]
+    t = np.linspace(0.0, 4, 1000)
+
+    y = [A * np.sin(2*np.pi*f[i]*t) for i in range(len(f))]
+    sum_y = sum(y)
+
+    for i in range(len(y)):
+        plt.subplot(4,1,i+1)
+        plt.plot(t, y[i])
+        plt.ylim(-4,4)
+        plt.title(r"$y=\sin 2 \pi ft $"+ f", f={f[i]}")
+
+    plt.tight_layout()
+    plt.show()
+
+    plt.plot(t, sum_y)
+    plt.title("sum of y")
+    plt.show()
+
+
+def merge_different_phase():
+    A, f = 1, 5
+    # phi = [0, 2*np.pi]
+    phi = [0, np.pi / 2]
+
+    # str_phi = [r"$0$", r"$2\pi$"]
+    str_phi = [r"$0$", r"$\pi / 2$"]
+    t = np.linspace(0.0, 2.0, 1000)
+
+    y = [A * np.sin(2*np.pi*f*t-phi[i]) for i in range(len(phi))]
+    sum_y = sum(y)
+
+    for i in range(len(y)):
+        plt.subplot(2,1,i+1)
+        plt.plot(t, y[i])
+        # plt.ylim(-4,4)
+        plt.title(r"$y=\sin (10 \pi t - \phi), \phi = $"+ str_phi[i])
+
+    plt.tight_layout()
+    plt.show()
+
+    plt.plot(t, sum_y)
+    plt.title("sum of y")
+    plt.ylim(-2,2)
+    plt.show()
+
+# merge_different_amp()
+# merge_different_freq()
+merge_different_phase()
\ No newline at end of file