Description Usage Arguments Details Value Author(s) See Also Examples
Computes naive predictions that are based on a few sites. These predictions
can then be used, e.g. in summary.predCVSTmodel
, to evaluate
how much better the spatial-temporal model performs compared to simple
(temporal) predictions.
The function requires one of location
and type
to be
specified, if both are given location
will be used over
type
. If type
is given locations such that
as.character(STmodel$locations$type) %in% type
will be
used.
1 | predictNaive(STmodel, locations = NULL, type = NULL)
|
STmodel |
|
locations |
Locations on which to base the naive predictions. |
type |
The type of sites to base the predictions on, uses the
(optional) field |
Given a set of locations the function computes 4 sets of naive prediction
for the observations in STmodel
:
The smooth trend in STmodel$trend
is fit to
all observations at the sites in
locations
using a linear regression. The
resulting smooth is used as a naive prediction for
all locations.
The temporal average over sites in locations
is
used as a naive prediction.
This fits the smooth trend in
STmodel$trend
to each site in
locations
; using the smooth at the
closest fixed site as a naive prediction.
This uses the observations at the closest site in
locations
to predict observations at all other
sites.
A list with items:
pred |
A (number of observations) - by - (6) data.frame containing
the four naive predictions described under |
locations |
The locations used for the naive predictions. |
Johan Lindstrom
Other STmodel functions: createCV
,
createDataMatrix
,
createSTmodel
,
dropObservations
,
estimateBetaFields
,
loglikeSTdim
, loglikeST
,
processLUR
, processLocation
,
updateCovf
,
updateTrend.STdata
Other cross-validation functions: computeLTA
,
createCV
, dropObservations
,
estimateCV.STmodel
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 | ##load data
data(mesa.model)
##naive predictions based on either AQS,
pred.aqs <- predictNaive(mesa.model, type="AQS")
##...or only one sites,
pred.1site <- predictNaive(mesa.model, locations="60372005")
##plot the predictions - The two cases that are constant in space
par(mfcol=c(2,1), mar=c(4.5,4.5,1,.5))
##observations as a function of date
plot(mesa.model, "loc.obs", type=as.factor(mesa.model$locations$ID),
legend.loc=NULL, pch=19, cex=.25)
##Add the predictions based on the smooth fitted to all sites
with(pred.aqs$pred, lines(date, smooth.fixed, col=1, lwd=2) )
with(pred.1site$pred, lines(date, smooth.fixed, col=2, lwd=2) )
##plot the predictions - One of the cases that vary in space, i.e. the smooth
##fit to the closest site.
##first extract as a data matrix
D <- with(pred.aqs$pred, createDataMatrix(obs=smooth.closest.fixed,
date=date, ID=ID) )
##observations as a function of date
##(only five sites for clarity)
mesa.model <- dropObservations(mesa.model, !(mesa.model$obs$idx %in% c(1,2,3,23,24)))
plot(mesa.model, "loc.obs", type=as.factor(mesa.model$locations$ID),
legend.loc=NULL, pch=19, cex=.25)
##Add the predictions based on the smooth
##fitted to the closest site
for(i in 1:5){
lines(as.Date(rownames(D)), D[,mesa.model$locations$ID[i]], col=i, lwd=2)
}
|
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