GR2: Generalised R2

Description

GR2 is a generic function that calculates and displays the generalised R2 value for fitted glmssn objects.

Usage

GR2(object)

Arguments

object

an object of class glmssn

Value

a numeric value equal to the GR2 for the specified glmssn object

Details

The generalised R2 value, or ‘coefficient of determination’, lies somewhere between 0 and 1, and is a general measure of the predictive power of a model. In this instance, it relates to the proportion of the variability in the data that is explained by the fixed effects.

Examples

Run this code


library(SSN)
# NOT RUN 
#mf04p <- importSSN(system.file("lsndata/MiddleFork04.ssn", 
#  package = "SSN"), predpts = "pred1km", o.write = TRUE)
#  use SpatialStreamNetwork object mf04p that was already created
data(mf04p)
#make sure mf04p has the correct path, will vary for each users installation
mf04p@path <- system.file("lsndata/MiddleFork04.ssn", package = "SSN")
    
# get some model fits stored as data objects
data(modelFits)
#NOT RUN use this one
#fitSp <- glmssn(Summer_mn ~ ELEV_DEM + netID,
#    ssn.object = mf04p, EstMeth = "REML", family = "Gaussian",
#    CorModels = c("Exponential.tailup","Exponential.taildown",
#    "Exponential.Euclid"), addfunccol = "afvArea")
#make sure fitSP has the correct path, will vary for each users installation
fitSp$ssn@path <- system.file("lsndata/MiddleFork04.ssn", package = "SSN")

GR2(fitSp)