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tools/sigmoid.py

@@ -0,0 +1,20 @@
+import numpy as np
+import matplotlib.pyplot as plt
+
+
+def lw(x, b=0):
+    x = np.clip(x, a_min=0.001, a_max=0.999)
+    snr = x/(1-x)
+    logsnr = np.log(snr)
+    # print(logsnr)
+    # return logsnr
+    weight =  1 / (1 + np.exp(-logsnr - b))#*(1-x)**2
+    return weight #/weight.max()
+
+x = np.arange(0.2, 0.8, 0.001)
+print(1/(x*(1-x)))
+for b in [0, 1, 2, 3]:
+    y = lw(x, b)
+    plt.plot(x, y, label=f"b={b}")
+plt.legend()
+plt.show()