Fowlkes Mallows Index (R)
The Fowlkes-Mallows Index is the geometric mean of precision and recall (see F-Score). This measure is based on the pairwise approach to calculate TP,TN,FP and FN.
\[ FM = \sqrt{\frac{TP}{TP+FP} \cdot \frac{TP}{TP+FN}} \]
In the binary classification background we have two classes that we want to distinguish:
positive and
negative.
In this scenario there are four possible outcomes:
- TP (True Positive): The object belongs to class positive and we classified it as positive,
- FP (False Positive ): The object belongs to class negative and we classified it as positive,
- TN (True Negative): The object belongs to class negative and we classified it as negative,
- FN (False Negative): The object belongs to class positive but we classified it as negative
| | Reality |
| | Positive | Negative |
Prediction | Positive | TP | FP |
Negative | FN | TN |