7) Output Logistic Regression Model as Probability.

This Blog entry is from the Logistic Regression section in Learn R.

The logistic regression output ranges from –5 to +5, yet oftentimes it is substantially more intuitive to present this output as a probability.  The formula to convert a logistic regression output to a probability is:

P = exp(Ouput) / (1+exp(Ouput))

It follows that vector arithmetic can be used, simply swapping the output with a vector of values created by the logistic regression model:


Run the line of script to console:


For completeness merge the probability values into the FraudRisk data frame:

FraudRisk <- mutate(FraudRisk, PAutomaticLogisticRegression)

Run the line of script to console: