R: Histogram of Raster objects.

histogram-methods {rasterVis}

R Documentation

Histogram of Raster objects.

Description

Draw histograms (with lattice) of Raster objects.

Usage

## S4 method for signature 'RasterLayer,missing'
histogram(x, data=NULL, maxpixels = 1e+05, nint=100, 
            xlab='', ylab='', main='', col='gray', ...)

## S4 method for signature 'RasterStackBrick,missing'
histogram(x, data=NULL, layers, FUN,
            maxpixels = 1e+05, nint=100,
            xlab='', ylab='', main='', col='gray',
            between=list(x=0.5, y=0.2),
            as.table=TRUE,
            scales=list(x=list(relation='free'),
              y=list(relation='free',
                draw=FALSE)),
            par.settings=rasterTheme(),
            ...)

## S4 method for signature 'formula,Raster'
histogram(x, data, dirXY,
            maxpixels = 1e+05,
            strip=TRUE,
            par.settings=rasterTheme(),...)

Arguments

`x`	A `Raster*` object or a `formula`.
`data`	`NULL` or a `Raster` object.
`layers`	A numeric or character which should indicate the layers to be displayed.
`dirXY`	A direction as a function of the coordinates (see `xyLayer`).
`FUN`	A function to applied to the `z` slot of a `RasterStackBrick` object. The result of this function is used as the grouping variable of the plot.
`nint`	Number of breaks for the histogram. See the documentation of `lattice::histogram` at lattice for details.
`maxpixels`	A numeric, for `sampleRandom`.
`xlab, ylab, main, col`	Arguments for `histogram`.
`between, as.table, scales, strip, par.settings`	Graphical parameters of `lattice`. See `lattice::xyplot` for details.
`...`	Additional arguments for `lattice::histogram`

Note

If you need different breakpoints in each panel, set breaks explicitely with NULL, a numeric or a character (for example, 'Sturges'; see hist for details)

Author(s)

Oscar Perpiñán Lamigueiro

Examples

f <- system.file("external/test.grd", package="raster")
r <- raster(f)
histogram(r)
s <- stack(r, r+500, r-500)
## Same breakpoints across panels
histogram(s)
## Each panel with different breakpoints
histogram(s, breaks=NULL)
histogram(s, breaks='Sturges')
histogram(s, breaks=30)


## Not run: 
##Solar irradiation data from CMSAF http://dx.doi.org/10.5676/EUM_SAF_CM/RAD_MVIRI/V001
old <- setwd(tempdir())
download.file('https://raw.github.com/oscarperpinan/spacetime-vis/master/data/SISmm2008_CMSAF.zip',
   'SISmm2008_CMSAF.zip', method='wget')
unzip('SISmm2008_CMSAF.zip')

listFich <- dir(pattern='\.nc')
stackSIS <- stack(listFich)
stackSIS <- stackSIS*24 ##from irradiance (W/m2) to irradiation Wh/m2

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

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

histogram(SISmm)
histogram(SISmm, FUN=as.yearqtr)

## With the formula interface you can create histograms for a set of variables
histogram(~ Jan + Dec, data=SISmm)
## Or use the coordinates for generating zonal histograms.
## For example, five histograms for each latitude zone  
histogram(~Jan|cut(y, 5), data=SISmm)
## More sophisticated bands can be defined using the dirXY argument 
histogram(~Jan|cut(dirXY, 5), dirXY = x^2 + y^2, data=SISmm)
 
setwd(old)

## End(Not run)

## Not run: 
##http://neo.sci.gsfc.nasa.gov/Search.html?group=64
pop <- raster('875430rgb-167772161.0.FLOAT.TIFF')
pop[pop==99999] <- NA
levelplot(pop, zscaleLog=10, par.settings=BTCTheme,
          panel=panel.levelplot.raster, interpolate=TRUE)

##http://neo.sci.gsfc.nasa.gov/Search.html?group=20
landClass <- raster('241243rgb-167772161.0.TIFF')
landClass[landClass==254] <- NA


s <- stack(pop, landClass)
names(s) <- c('pop', 'landClass')

histogram(~asinh(pop)|landClass, data=s,
            scales=list(relation='free'),
            strip=strip.custom(strip.levels=TRUE))

## End(Not run)

[Package rasterVis version 0.32 Index]