TwoStepBootstrap: Estimation and Inference for Two-Step Estimators

Description Usage Arguments Value Methods (by generic) See Also Examples

View source: R/TwoStepBootstrap.R

Description

This function implements the esmation and inference for two-step estimators including Krig-and-regress(OLS), Krig-and-regress(GLS), two-step bootstrap.

Usage

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TwoStepBootstrap(DatR, VarR, DatY, VarY, variogram.model,
                   is.cov.misspecified, is.den.misspecified,
                   plot.start.value = TRUE, cutoff.R, cutoff.res,
                   start.value.method = 2, projected = FALSE)

## S3 method for class 'TwoStepBootstrap'
summary(object, ...)

Arguments

DatR

explanatory variable R, a spatial object, see coordintes()

VarR

name of variable R

DatY

outcome variable Y, a spatial object, see coordintes()

VarY

name of variable Y

variogram.model

variogram model type, e.g. "Exp", "Sph", "Gau", "Mat"

is.cov.misspecified

logical; if TRUE, the covariance function is misspecified

is.den.misspecified

logical; if TRUE, the density function is not Gaussian distribution.

plot.start.value

logical, if TRUE, plot the variogram and the fitted variogram curve corresponding to starting values

cutoff.R

cutoff for sample variogram of variable R

cutoff.res

cutoff for sample variogram of regression residuals

start.value.method

fitting method, see fit.variogram()

projected

logical; if FALSE, data are assumed to be unprojected, meaning decimal longitude/latitude. For projected data, Euclidian distances are computed, for unprojected great circle distances(km) are computed.

object

class TwoStepBootstrap objects.

Value

num.obs

the number of observations

vario.par.point.est

point estimates for variogram parameters(psill, range)

vario.par.var.mat

estimated variance-covariance matrix for variogram parameters(psill, range)

ols.point.est

point estimates for Krig-and-OLS estimator

ols.var.mat

estimated variance-covariance matrix for Krig-and-OLS estimator

gls.point.est

point estimates for Krig-and-GLS estimator

gls.var.mat

estimated variance-covariance matrix for Krig-and-GLS estimator

tsbs.point.est

point estimates for Two-Step Bootstrap estimator

tsbs.var.mat

estimated variance-covariance matrix for Two-Step Bootstrap estimator

Methods (by generic)

See Also

sp, gstat

Examples

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library(SpReg)
rivers <- read.csv(system.file("extdata", "rivers.csv", package = "SpReg"))

rivers <- rivers[which(rivers$FOR_NLCD<100),]
train_set <- sample(1:558,277);
test_set <- setdiff(1:558,train_set);
rivers_train <- rivers[train_set, ];
rivers_test <- rivers[test_set, ];

DatR <- rivers_train[,c("FOR_NLCD", "LAT_DD", "LON_DD")];
DatR$X <- log((DatR$FOR_NLCD)/(100-DatR$FOR_NLCD));
sp::coordinates(DatR) <- ~LON_DD+LAT_DD;
sp::proj4string(DatR) =  "+proj=longlat +datum=WGS84";
DatY <- rivers_test[, c("CL","LAT_DD","LON_DD")];
DatY$Y <- log(DatY$CL);
sp::coordinates(DatY) <- ~LON_DD+LAT_DD;
sp::proj4string(DatY) =  "+proj=longlat +datum=WGS84";

TwoStep_Results <- TwoStepBootstrap(DatR, "X", DatY, "Y", "Exp", FALSE, FALSE,
                                    cutoff.R = 295, cutoff.res = 40);

zhenxie23/SpReg documentation built on March 26, 2021, 3:09 a.m.