specificity: Specificity
In wgaul/wgutil: Willson's common ecological data analysis functions

Description Usage Arguments Details Value Examples

Measure specificity of a classifier

1	specificity(threshold, responses, predictions, na.rm = FALSE)

`threshold`	a numeric threshold. Values of predictions greater than this threshold will be predicted to be positive
`responses`	a vector of binary responses (TRUE/FALSE or 1/0) to be predicted
`predictions`	a vector of numeric predicted values that can be converted to binary predictions using threshold
`na.rm`	if TRUE, NA values will be removed before computing sensitivity

This function calculates specificity given predictions, responses, and a prediction threshold.

specificity = TN / N

where TN is the number of True Negatives (correctly rejected negative responses) and N is the total number of negative responses.

the specificity when prediction responses using predictions at the given threshold

# observed (binary) values
resp <- c(1, 0, 1, 1, 0, 1,
        0, 1, 1, 1, 0, 0)

# predicted values
pred <- c(0.75, 0.7, 0.63,
          0.7, 0.4, 0.52,
         0.6, 0.9, 0.3, 0.2,
         0.4, 0.3)

specificity(threshold = 0.5, responses = resp, predictions = pred)