Exercise

# Defining Zhang's metric

In general, when we want to perform a task many times, we'll write a function, rather than coding up each individual instance. In this exercise, we'll define a function for Zhang's metric that takes an antecedent and consequent and outputs the metric itself. When the problems we solve become increasingly complicated in the following chapter, having a convenient means of computing a metric will greatly simplify things.

Note that `numpy`

has been imported as `np`

and `pandas`

has been imported as `pd`

. Additionally, recall that the expression for Zhang's metric in terms of support calculations is the following:

$$Zhang(A \rightarrow B) = $$ $$\frac{Support(A \& B) - Support(A) Support(B)}{ max[Support(AB) (1-Support(A)), Support(A)(Support(B)-Support(AB)]}$$

Instructions

**100 XP**

- Define the support values of the antecedent and consequent individually.
- Define the support of
*{antecedent, consequent}*. - Complete the expressions for the numerator and denominator.
- Complete the expression for Zhang's metric.