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GWmodel (version 2.4-1)

gtwr: Geographically and Temporally Weighted Regression

Description

A function for calibrating a Geographically and Temporally Weighted Regression (GTWR) model.

Usage

gtwr(formula, data, regression.points, obs.tv, reg.tv, st.bw, kernel="bisquare",
     adaptive=FALSE, p=2, theta=0, longlat=F,lamda=0.05,t.units = "auto",ksi=0,
     st.dMat)

Value

A list of class “gtwrm”:

GTW.arguments

a list class object including the model fitting parameters for generating the report file

GTW.diagnostic

a list class object including the diagnostic information of the model fitting

lm

an object of class inheriting from “lm”, see lm.

SDF

a SpatialPointsDataFrame (may be gridded), or SpatialPolygonsDataFrame object (see package “sp”), or sf object (see package “sf”) integrated with regression.points, GTWR coefficient estimates, y value,predicted values, coefficient standard errors and t-values in its "data" slot.

timings

starting and ending time.

this.call

the function call used.

Arguments

formula

Regression model formula of a formula object

data

a Spatial*DataFrame, i.e. SpatialPointsDataFrame or SpatialPolygonsDataFrame as defined in package sp, or a sf object defined in package sf

regression.points

a Spatial*DataFrame object, i.e. SpatialPointsDataFrame or SpatialPolygonsDataFrame as defined in package sp; Note that no diagnostic information will returned if it is assigned

obs.tv

a vector of time tags for each observation, which could be numeric or of POSIXlt class

reg.tv

a vector of time tags for each regression location, which could be numeric or of POSIXlt class

st.bw

spatio-temporal bandwidth used in the weighting function, possibly calculated by bw.gwr;fixed (distance) or adaptive bandwidth(number of nearest neighbours)

kernel

function chosen as follows:

gaussian: wgt = exp(-.5*(vdist/bw)^2);

exponential: wgt = exp(-vdist/bw);

bisquare: wgt = (1-(vdist/bw)^2)^2 if vdist < bw, wgt=0 otherwise;

tricube: wgt = (1-(vdist/bw)^3)^3 if vdist < bw, wgt=0 otherwise;

boxcar: wgt=1 if dist < bw, wgt=0 otherwise

adaptive

if TRUE calculate an adaptive kernel where the bandwidth (bw) corresponds to the number of nearest neighbours (i.e. adaptive distance); default is FALSE, where a fixed kernel is found (bandwidth is a fixed distance)

p

the power of the Minkowski distance, default is 2, i.e. the Euclidean distance

theta

an angle in radians to rotate the coordinate system, default is 0

longlat

if TRUE, great circle distances will be calculated

lamda

an parameter between 0 and 1 for calculating spatio-temporal distance

t.units

character string to define time unit

ksi

an parameter between 0 and PI for calculating spatio-temporal distance, see details in Wu et al. (2014)

st.dMat

a pre-specified spatio-temporal distance matrix, and can be calculated via the function st.dist

Author

Binbin Lu binbinlu@whu.edu.cn

References

Huang, B., Wu, B., & Barry, M. (2010). Geographically and temporally weighted regression for modeling spatio-temporal variation in house prices. International Journal of Geographical Information Science, 24, 383-401.

Wu, B., Li, R., & Huang, B. (2014). A geographically and temporally weighted autoregressive model with application to housing prices. International Journal of Geographical Information Science, 28, 1186-1204.

Fotheringham, A. S., Crespo, R., & Yao, J. (2015). Geographical and Temporal Weighted Regression (GTWR). Geographical Analysis, 47, 431-452.