postResample: Calculates performance across resamples
Description
Given two numeric vectors of data, the mean squared error and R-squared
are calculated. For two factors, the overall agreement rate and Kappa are
determined.
Usage
postResample(pred, obs)
Arguments
pred
A vector of numeric data (could be a factor)
obs
A vector of numeric data (could be a factor)
Value
A vector of performance estimates.
Details
This function is meant to be used with apply across a matrix. For numeric data
the code checks to see if the standard deviation of either vector is zero. If so, the correlation
between those samples is assigned a value of zero. NA values are ignored everywhere.
Note that many models have more predictors (or parameters) than data points, so the typical mean squared
error denominator (n - p) does not apply. Root mean squared error is calculated using sqrt(mean((pred - obs)^2.
Also, R-squared is calculated as the square of the correlation between the observed and predicted outcomes.