data: (Optional) argument to call an existing data frame containing the data.
obs: Vector with observed values (numeric).
pred: Vector with predicted values (numeric).
tidy: Logical operator (TRUE/FALSE) to decide the type of return. TRUE returns a data.frame, FALSE returns a list; Default : FALSE.
na.rm: Logic argument to remove rows with missing values (NA). Default is na.rm = TRUE.
Returns
an object of class numeric within a list (if tidy = FALSE) or within a data frame (if tidy = TRUE).
Details
The r coefficient measures the strength of linear relationship between two variables. It only accounts for precision, but it is not sensitive to lack of prediction accuracy. It is a normalized, dimensionless coefficient, that ranges between -1 to 1. It is expected that predicted and observed values will show 0 < r < 1. It is also known as the Pearson Product Moment Correlation, among other names. For the formula and more details, see online-documentation
Examples
set.seed(1)X <- rnorm(n =100, mean =0, sd =10)Y <- X + rnorm(n=100, mean =0, sd =3)r(obs = X, pred = Y)
References
Kirch (2008) Pearson’s Correlation Coefficient. In: Kirch W. (eds) Encyclopedia of Public Health. Springer, Dordrecht.