histogram-methods function

Histogram of Raster objects.

Draw histograms (with lattice) of Raster objects. methods

## S4 method for signature 'Raster,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)),
            names.attr,
            par.settings=rasterTheme(),
            att = 1,
            ...)

## S4 method for signature 'SpatRaster,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)),
            names.attr,
            par.settings=rasterTheme(),
            att = 1,
            ...)

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

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

Arguments

• x: A Raster* object, a SpatRaster object or a formula.

• data: NULL, a Raster object, or SpatRaster 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 or to the time index of the SpatRaster 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 or spatSample.

• att: If x is a factor, integer or character to choose which variable (column) in the RAT table should be used.

• xlab, ylab, main, col: Arguments for histogram.

• names.attr: Character or expression, names to use in each panel. If missing its default value is the result of names(x)

  (after subsetting the layers to be displayed).

• 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

See Also

histogram,xscale.raster, yscale.raster, rasterTheme

Examples

library(raster)
library(terra)

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)

## Categorical data
r <- raster(nrow=10, ncol=10)
r[] = 1
r[51:100] = 3
r[3:6, 1:5] = 5
r <- ratify(r)
     
rat <- levels(r)[[1]]
rat$landcover <- c('Pine', 'Oak', 'Meadow')
rat$class <- c('A1', 'B2', 'C3')
levels(r) <- rat

histogram(r)
histogram(r, att = "class")

## Not run:

library(zoo)

dataURL <- "https://raw.github.com/oscarperpinan/bookvis/master/data/"

##Solar irradiation data from CMSAF http://dx.doi.org/10.5676/EUM_SAF_CM/RAD_MVIRI/V001
old <- setwd(tempdir())
download.file(paste0(dataURL, "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)