# File br2.R
# Part of the hydroGOF R package, https://github.com/hzambran/hydroGOF
# https://cran.r-project.org/package=hydroGOF
# http://www.rforge.net/hydroGOF/ ;
# Copyright 2009-2024 Mauricio Zambrano-Bigiarini
# Distributed under GPL 2 or later
################################################################################
# 'br2': Weighted R2 #
# Coef. of determination multiplied by the coef. of the regression line #
################################################################################
# Author: Mauricio Zambrano-Bigiarini #
################################################################################
# Started: 27-Oct-2009 #
# Updates: 11-Mar-2020 #
# 16-Jan-2023 ; 29-Nov-2023 #
# 20-Jan-2024 #
################################################################################
# This index allows accounting for the discrepancy in the magnitude of two signals
# under or overpredictions, (depicted by 'b') as well as their dynamics (depicted by R2).
# Krause, P., Boyle, D. P., and Base, F.: Comparison of different efficiency
# criteria for hydrological model assessment, Adv. Geosci., 5, 89-97, 2005
# Krstic, G., Krstic, N. S., Zambrano-Bigiarini, M. (2016).
# The br2-weighting Method for Estimating the Effects of Air Pollution on
# Population Health. Journal of Modern Applied Statistical Methods, 15(2), 42.
# doi:10.22237/jmasm/1478004000}
br2 <-function(sim, obs, ...) UseMethod("br2")
# 'obs' : numeric 'data.frame', 'matrix' or 'vector' with observed values
# 'sim' : numeric 'data.frame', 'matrix' or 'vector' with simulated values
# 'Result': weighted R2 between 'sim' and 'obs'
br2.default <- function(sim, obs, na.rm=TRUE, use.abs=FALSE, fun=NULL, ...,
epsilon.type=c("none", "Pushpalatha2012", "otherFactor", "otherValue"),
epsilon.value=NA){
if ( is.na(match(class(sim), c("integer", "numeric", "ts", "zoo"))) |
is.na(match(class(obs), c("integer", "numeric", "ts", "zoo")))
) stop("Invalid argument type: 'sim' & 'obs' have to be of class: c('integer', 'numeric', 'ts', 'zoo')")
# the next two lines are required for avoiding an strange behaviour
# of the difference function when sim and obs are time series.
if ( !is.na(match(class(sim), c("ts", "zoo"))) ) sim <- as.numeric(sim)
if ( !is.na(match(class(obs), c("ts", "zoo"))) ) obs <- as.numeric(obs)
# Checking 'epsilon.type'
epsilon.type <- match.arg(epsilon.type)
# index of those elements that are present both in 'sim' and 'obs' (NON- NA values)
vi <- valindex(sim, obs)
if (length(vi) > 0) {
# Filtering 'obs' and 'sim', selecting only those pairs of elements
# that are present both in 'x' and 'y' (NON- NA values)
obs <- obs[vi]
sim <- sim[vi]
if (!is.null(fun)) {
fun1 <- match.fun(fun)
new <- preproc(sim=sim, obs=obs, fun=fun1, ...,
epsilon.type=epsilon.type, epsilon.value=epsilon.value)
sim <- new[["sim"]]
obs <- new[["obs"]]
} # IF end
# Computing the linear regression between 'sim' and 'obs',
# forcing a zero intercept.
x.lm <- lm(sim ~ obs - 1)
# Getting the slope of the previous linear regression
b <- as.numeric( coefficients(x.lm)["obs"] )
# computing the r2
#r2 <- (.rPearson(sim, obs))^2 # this works only for linear models.
# https://github.com/hzambran/hydroGOF/issues/16#issue-1736556320
r2 <- R2(sim=sim, obs=obs)
if (!(use.abs)) {
br2 <- ifelse(b <= 1, r2*abs(b), r2/abs(b))
} else br2 <- ifelse(abs(b) <= 1, r2*abs(b), r2/abs(b))
} else {
br2 <- NA
warning("There are no pairs of 'sim' and 'obs' without missing values !")
} # ELSE end
return(br2)
} # 'br2' END
################################################################################
# 'br2': Weighted R2 #
# Coef. of determination multiplied by the coef. of the regression line #
################################################################################
# Started: 27-Oct-2009 #
# Updates: 11-Mar-2020 #
# 16-Jan-2023 #
################################################################################
br2.matrix <- function(sim, obs, na.rm=TRUE, use.abs=FALSE, fun=NULL, ...,
epsilon.type=c("none", "Pushpalatha2012", "otherFactor", "otherValue"),
epsilon.value=NA){
# Checking that 'sim' and 'obs' have the same dimensions
if ( all.equal(dim(sim), dim(obs)) != TRUE )
stop( paste("Invalid argument: dim(sim) != dim(obs) ( [",
paste(dim(sim), collapse=" "), "] != [",
paste(dim(obs), collapse=" "), "] )", sep="") )
br2 <- rep(NA, ncol(obs))
br2 <- sapply(1:ncol(obs), function(i,x,y) {
br2[i] <- br2.default( x[,i], y[,i], na.rm=na.rm, use.abs=use.abs,
fun=fun, ...,
epsilon.type=epsilon.type,
epsilon.value=epsilon.value)
}, x=sim, y=obs )
return(br2)
} # 'br2.matrix' END
################################################################################
# 'br2': Weighted R2 #
# Coef. of determination multiplied by the coef. of the regression line #
################################################################################
# Started: 27-Oct-2009 #
# Updates: 11-Mar-2020 #
# 16-Jan-2023 #
################################################################################
br2.data.frame <- function(sim, obs, na.rm=TRUE, use.abs=FALSE, fun=NULL, ...,
epsilon.type=c("none", "Pushpalatha2012", "otherFactor", "otherValue"),
epsilon.value=NA){
sim <- as.matrix(sim)
obs <- as.matrix(obs)
br2.matrix(sim, obs, na.rm=na.rm, use.abs=use.abs, fun=fun, ...,
epsilon.type=epsilon.type, epsilon.value=epsilon.value)
} # 'br2.data.frame' END
################################################################################
# Author: Mauricio Zambrano-Bigiarini #
################################################################################
# Started: 22-Mar-2013 #
# Updates: 11-Mar-2020 #
################################################################################
br2.zoo <- function(sim, obs, na.rm=TRUE, use.abs=FALSE, fun=NULL, ...,
epsilon.type=c("none", "Pushpalatha2012", "otherFactor", "otherValue"),
epsilon.value=NA){
sim <- zoo::coredata(sim)
if (is.zoo(obs)) obs <- zoo::coredata(obs)
if (is.matrix(sim) | is.data.frame(sim)) {
br2.matrix(sim, obs, na.rm=na.rm, use.abs=use.abs, fun=fun, ...,
epsilon.type=epsilon.type, epsilon.value=epsilon.value)
} else NextMethod(sim, obs, na.rm=na.rm, use.abs=use.abs, fun=fun, ...,
epsilon.type=epsilon.type, epsilon.value=epsilon.value)
} # 'br2.zoo' end
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