Correcting the Gaussian Formula (#2249)

* Correcting the Gaussian Formula

I have added the parenthesis around the 2*sigma^2 term.

* Update gaussian.py

* Update gaussian.py

* Update gaussian.py

* Update gaussian.py

* Update gaussian.py

* Update gaussian.py

Co-authored-by: Christian Clauss <[email protected]>

Author: aryan26roy

Diff for: maths/gaussian.py

@@ -1,9 +1,5 @@
 """
 Reference: https://en.wikipedia.org/wiki/Gaussian_function
-
-python/black : True
-python : 3.7.3
-
 """
 from numpy import exp, pi, sqrt
 
@@ -16,6 +12,12 @@ def gaussian(x, mu: float = 0.0, sigma: float = 1.0) -> int:
     >>> gaussian(24)
     3.342714441794458e-126
 
+    >>> gaussian(1, 4, 2)
+    0.06475879783294587
+
+    >>> gaussian(1, 5, 3)
+    0.05467002489199788
+
     Supports NumPy Arrays
     Use numpy.meshgrid with this to generate gaussian blur on images.
     >>> import numpy as np
@@ -49,8 +51,8 @@ def gaussian(x, mu: float = 0.0, sigma: float = 1.0) -> int:
 
     >>> gaussian(2523, mu=234234, sigma=3425)
     0.0
-  """
-    return 1 / sqrt(2 * pi * sigma ** 2) * exp(-((x - mu) ** 2) / 2 * sigma ** 2)
+    """
+    return 1 / sqrt(2 * pi * sigma ** 2) * exp(-((x - mu) ** 2) / (2 * sigma ** 2))
 
 
 if __name__ == "__main__":