Binary classification measure defined as $$\frac{\mathrm{TN}}{\mathrm{FN} + \mathrm{TN}}.$$

npv(truth, response, positive, na_value = NaN, ...)

## Arguments

truth :: factor() True (observed) labels. Must have the exactly same two levels and the same length as response. :: factor() Predicted response labels. Must have the exactly same two levels and the same length as truth. :: character(1) Name of the positive class. :: numeric(1) Value that should be returned if the measure is not defined for the input (as described in the note). Default is NaN. :: any Additional arguments. Currently ignored.

## Value

Performance value as numeric(1).

## Note

This measure is undefined if FN + TN = 0.

## Meta Information

• Type: "binary"

• Range: $$[0, 1]$$

• Minimize: FALSE

• Required prediction: response

## References

https://en.wikipedia.org/wiki/Template:DiagnosticTesting_Diagram