biovars: bioclimatic variables

In dismo: Species Distribution Modeling

Description

Function to create 'bioclimatic variables' from monthly climate data.

Usage

biovars(prec, tmin, tmax, ...) 

Arguments

prec	vector, matrix, or RasterStack/Brick of precipitation data
tmin	vector, matrix, or RasterStack/Brick of minimum temperature data
tmax	vector, matrix, or RasterStack/Brick of maximum temperature data
...	Additional arguments

Details

Input data is normaly monthly. I.e. there should be 12 values (layers) for each variable, but the function should also work for e.g. weekly data (with some changes in the meaning of the output variables. E.g. #8 would then not be for a quater (3 months), but for a 3 week period).

Value

Depending on the class of the input data, an object of class 'vector', 'matrix' or 'RasterBrick' with 19 variables (columns, layers)

bio1 = Mean annual temperature

bio2 = Mean diurnal range (mean of max temp - min temp)

bio3 = Isothermality (bio2/bio7) (* 100)

bio4 = Temperature seasonality (standard deviation *100)

bio5 = Max temperature of warmest month

bio6 = Min temperature of coldest month

bio7 = Temperature annual range (bio5-bio6)

bio8 = Mean temperature of the wettest quarter

bio9 = Mean temperature of driest quarter

bio10 = Mean temperature of warmest quarter

bio11 = Mean temperature of coldest quarter

bio12 = Total (annual) precipitation

bio13 = Precipitation of wettest month

bio14 = Precipitation of driest month

bio15 = Precipitation seasonality (coefficient of variation)

bio16 = Precipitation of wettest quarter

bio17 = Precipitation of driest quarter

bio18 = Precipitation of warmest quarter

Author(s)

Robert J. Hijmans

Examples

tmin <- c(10,12,14,16,18,20,22,21,19,17,15,12)
tmax <- tmin + 5
prec <- c(0,2,10,30,80,160,80,20,40,60,20,0)
biovars(prec, tmin, tmax)

tmn = tmx = prc = brick(nrow=1, ncol=1)
tmn <- setValues(tmn, t(matrix(c(10,12,14,16,18,20,22,21,19,17,15,12))))
tmx <- tmn + 5
prc <- setValues(prc, t(matrix(c(0,2,10,30,80,160,80,20,40,60,20,0))))
b <- biovars(prc, tmn, tmx)
as.matrix(b)

Example output

Loading required package: raster
Loading required package: sp
         bio1 bio2     bio3     bio4 bio5 bio6 bio7 bio8     bio9 bio10
[1,] 18.83333    5 29.41176 384.5501   27   10   17 22.5 13.83333  23.5
        bio11 bio12 bio13 bio14    bio15 bio16 bio17 bio18 bio19
[1,] 13.83333   502   160     0 109.9637   320     2   260     2
NOTE: rgdal::checkCRSArgs: no proj_defs.dat in PROJ.4 shared files
NOTE: rgdal::checkCRSArgs: no proj_defs.dat in PROJ.4 shared files
NOTE: rgdal::checkCRSArgs: no proj_defs.dat in PROJ.4 shared files
         bio1 bio2     bio3     bio4 bio5 bio6 bio7 bio8     bio9 bio10
[1,] 18.83333    5 29.41176 384.5501   27   10   17 22.5 13.83333  23.5
        bio11 bio12 bio13 bio14    bio15 bio16 bio17 bio18 bio19
[1,] 13.83333   502   160     0 109.9637   320     2   260     2

dismo documentation built on May 2, 2019, 6:07 p.m.