GR2: Generalised R2

In jayverhoef/SSN: Spatial Modeling on Stream Networks

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

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.

Value

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

Author(s)

Jay Ver Hoef [e-mail]

See Also

glmssn

Examples

library(SSN)
#for examples, copy MiddleFork04.ssn directory to R's temporary directory
copyLSN2temp()
# NOT RUN
# Create a SpatialStreamNetork object that also contains prediction sites
#mf04p <- importSSN(paste0(tempdir(),'/MiddleFork04.ssn'), 
#  predpts = "pred1km", o.write = TRUE)
#use mf04p SpatialStreamNetwork object, already created
data(mf04p)
#for examples only, make sure mf04p has the correct path
#if you use importSSN(), path will be correct
mf04p <- updatePath(mf04p, paste0(tempdir(),'/MiddleFork04.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")
#for examples only, make sure fitSp has the correct path
#if you use importSSN(), path will be correct
fitSp$ssn.object <- updatePath(fitSp$ssn.object, 
	paste0(tempdir(),'/MiddleFork04.ssn'))

GR2(fitSp)

jayverhoef/SSN documentation built on May 1, 2023, 1:04 p.m.