rasterVis (version 0.31)

horizonplot-methods: Horizon plots of Raster objects.

Description

This method draws horizon graphs for each zone as calculated with zonal from the directions defined by xyLayer

Usage

## S3 method for class 'RasterStackBrick,missing':
horizonplot(x, data = NULL,
    dirXY = y, stat = 'mean', digits = 0,
    origin = mean, 
    xlab = 'Time', ylab = 'direction',
    colorkey = TRUE, colorkey.digits = 1,
    scales=list(y = list(relation = "same")),
    ...)

docType

methods

Details

(Extracted from the reference): "The horizon graph allows to examine how a large number of items changed through time, to spot extraordinary behaviors and predominant patterns, view each of the items independently from the others when they wish, make comparisons between the items, and view changes that occurred with enough precision to determine if further examination is required."

References

http://www.perceptualedge.com/articles/visual_business_intelligence/time_on_the_horizon.pdf

See Also

horizonplot, xyplot, levelplot.

Examples

library(zoo)

url <- "ftp://ftp.wiley.com/public/sci_tech_med/spatio_temporal_data/"
sst.dat = read.table(paste(url, "SST011970_032003.dat", sep=''), header = FALSE) 
sst.ll = read.table(paste(url, "SSTlonlat.dat", sep=''), header = FALSE)

spSST <- SpatialPointsDataFrame(sst.ll, sst.dat)
gridded(spSST) <- TRUE
proj4string(spSST) = "+proj=longlat +datum=WGS84"
SST <- brick(spSST)

idx <- seq(as.Date('1970-01-01'), as.Date('2003-03-01'), by='month')
idx <- as.yearmon(idx)
SST <- setZ(SST, idx)
names(SST) <- as.character(idx)

horizonplot(SST)

horizonplot(SST, stat='sd')

## Different scales for each panel, with colors representing deviations
## from the origin in *that* panel
horizonplot(SST, scales=list('free'))

## origin may be a function...
horizonplot(SST, origin=mean)
## ...or a number
horizonplot(SST, origin=0)

## A different color palette
horizonplot(SST, origin=0, col.regions=brewer.pal(n=6, 'PuOr'))

## The width of each color segment can be defined with horizonscale
horizonplot(SST, horizonscale=1, origin=0)

old <- getwd()
##change to your folder...
setwd('CMSAF')
listFich <- dir(pattern='2008')
stackSIS <- stack(listFich)
stackSIS <- stackSIS*24 ##from irradiance (W/m2) to irradiation Wh/m2
setwd(old)

idx <- seq(as.Date('2008-01-15'), as.Date('2008-12-15'), 'month')

SISmm <- setZ(stackSIS, idx)
names(SISmm) <- month.abb

horizonplot(SISmm)