plotfields: Plot of weather fields

Description

Plot weather fields.

Usage

plotfields(field, x.lim, y.lim, country.outline="US", title)

Arguments

field

numeric square matrix containing the values of the weather field on a grid.

x.lim

numeric vector giving the smallest and the largest longitude to be displayed.

y.lim

numeric vector giving the smallest and the largest latitude to be displayed.

country.outline

character string indicating which country to outline in the plot. Possible values are "US", "world" or "both". If "US" is specified, a medium resolution outline of the US with the states and bodies of water is added to plot. If "world" is specified, a medium resolution of bodies of land and mass of water delimited by the smallest and largest latitude and longitude specified in x.lim and y.lim is added to the plot. If country.outline is set equal to both, medium resolution of both the US and of the bodies of land and water enclosed between the specified latitude and longitude are added to the plot. Default value is "US".

title

character string with the title for the plot.

Value

The function returns a graphical display of the weather field on a region delimited by the lower and upper bound for the longitude and the latitude.

References

Gel, Y., Raftery, A. E., Gneiting, T. (2004). Calibrated probabilistic mesoscale weather field forecasting: The Geostatistical Output Perturbation (GOP) method (with discussion). Journal of the American Statistical Association, Vol. 99 (467), 575--583.

Nychka, D. (2004). The fields package. Available at: http:lib.stat.cmu.edu/R/CRAN/doc/package/fields.pdf.

Examples

Run this code

## Loading data
library(fields)
library(RandomFields)
data(slp)
data(gridlong)
data(gridlat)
data(forecast.grid)
day <- slp$date.obs
id <- slp$id.stat
coord1 <- slp$lon.stat
coord2 <- slp$lat.stat
obs <- slp$obs
forecast <- slp$forecast
coord1.grid <- gridlong$gridded.long
coord2.grid <- gridlat$gridded.lat
forecast.grid <- forecast.grid$gridded.forecast

## Computing the empirical variogram
variogram <- Emp.variog(day,obs,forecast,id,coord1,coord2,cut.points=NULL,
max.dist=NULL,nbins=NULL)

## Estimating parameters
param.est <- Variog.fit(variogram,"exponential",max.dist.fit=NULL,
init.val=NULL,fix.nugget=FALSE)

## Simulating realizations of the weather random field
simul <- Field.sim(obs, forecast, coord1.grid, coord2.grid, forecast.grid,
variog.model="exponential", param.est=c(param.est$nugget,param.est$variance,
param.est$range), n.sim=4, n.displ=0, qt.displ=c(10,50,90))

##Plotting one of the simulated weather random fields
par(mfrow=c(1,1),mai=c(0.8,0.8,0.8,0.8))
plotfields(simul$sim.fields[,,1],x.lim=c(min(coord1.grid),max(coord1.grid)),
y.lim=c(min(coord2.grid),max(coord2.grid)),country.outline="US",title="Simulated weather field")

## Plotting one of the percentiles of the weather field
par(mfrow=c(1,1),mai=c(0.8,0.8,0.8,0.8))
plotfields(simul$pct.fields[,,1],x.lim=c(min(coord1.grid),max(coord1.grid)),
y.lim=c(min(coord2.grid),max(coord2.grid)),country.outline="US",title="10th percentile")