doc of normalizer

Author: RomanJuranek

pclines/accumulator.py

@@ -64,19 +64,79 @@ def _validate_bbox(bbox):
 
 class Normalizer:
     """
-    Range mapping
+    Linear mapping of ranges
+
+    The class maps values from source range (a,b) to a destination
+    range (c,d) by scaling and offset.
+
+    The `transform` then maps a to c and b to d. The `inverse`
+    then does inverse transform.
     """
     def __init__(self, src_range, dst_range=(0,1)):
+        """
+        Inputs
+        ------
+        src_range, dst_range: tuple
+            A tuple with two values [a, b] of source and destination ranges
+
+        Example
+        -------
+        >> T = Normalizer((0,10), (1,-1))
+        >> T.transform(10)
+        -1
+        >> T.transform(6)
+        -0.2
+        >> T.inverse(-1)
+        10
+        """
         # TODO: check ranges
         self.w, self.b = _linear_transform(src_range, dst_range)
         self.wi, self.bi = _linear_transform(dst_range, src_range)
 
     def transform(self, x):
-        """ src -> dst mapping of x """
+        """ src -> dst mapping of x
+
+        Transforms values of x from source range to destination range.
+        
+        Inputs
+        ------
+        x : ndarray
+            values to transform
+
+        Outputs
+        -------
+        y : ndarray
+            Transformed x
+
+        Example
+        -------
+        >> T = Normalizer((0, 100), (0, 1))
+        >> T(50)
+        0.5
+        """
         return self.w * x + self.b
 
     def inverse(self, x):
-        """ dst -> src mapping of x """
+        """ dst -> src mapping of x
+        
+        Transforms values of x from destination range to the source range.
+        
+        Inputs
+        ------
+        x : ndarray
+            values to transform
+
+        Outputs
+        -------
+        y : ndarray
+            Transformed x
+
+        Example
+        -------
+        >> T = Normalizer((0, 100), (0, 1))
+        >> T(0.5)
+        50
+        """
         return self.wi * x + self.bi
 
     __call__ = transform