This function computes the standard error of the estimate based on the actual and predicted values
see(true, pred)a numeric vector representing the true values
a numeric vector representing the predicted values, must be equal length to true
Function returns a length one value of the standard error of the estimate
This function calculates the standard error of the estimate (see) as a scaled residual, so: $$ see=\sqrt{\frac{\sum \left ( true-pred \right )^{2}}{N}} $$