turicreate.toolkits.distances.transformed_dot_product¶

turicreate.toolkits.distances.
transformed_dot_product
(x, y)¶ Compute the “transformed_dot_product” distance between two dictionaries or two lists of equal length. This is a way to transform the dot product of the two inputs—a similarity measure—into a distance measure. Suppose x and y each contain \(d\) variables:
\[D(x, y) = \log\{1 + \exp\{\sum_i^d x_i y_i\}\}\]Warning
The ‘dot_product’ distance is deprecated and will be removed in future versions of Turi Create. Please use ‘transformed_dot_product’ distance instead, although note that this is more than a name change; it is a different transformation of the dot product of two vectors. Please see the distances module documentation for more details.
Parameters:  x : dict or list
First input vector.
 y : dict or list
Second input vector.
Returns:  out : float
Notes
 If the input vectors are in dictionary form, keys missing in one of the two dictionaries are assumed to have value 0.
 Transformed dot product distance is not a metric because the distance from a point to itself is not 0. This means the ball tree cannot be used to compute nearest neighbors based on this distance.
Examples
>>> tc.distances.transformed_dot_product([1, 2, 3], [4, 5, 6]) 0.03125 ... >>> tc.distances.transformed_dot_product({'a': 2, 'c': 4}, {'b': 3, 'c': 12}) 0.020833333333333332