bbgdm: bbgdm objects

Description Usage Arguments Value References Examples

Description

creates a bbgdm model, comprising multiple gdms. bbgdm models are core of bbgdm, different parameterisation can be achieve similar to a glm, see bbgdm.fit for more details.

Usage

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bbgdm(form, sp.dat, env.dat, family = "binomial", link = "logit",
  dism_metric = "number_non_shared", nboot = 100, spline_type = "ispline",
  spline_df = 2, spline_knots = 1, geo = FALSE, geo.type = "euclidean",
  coord.names = c("X", "Y"), optim.meth = "nlmnib", est.var = FALSE,
  trace = FALSE, prior = FALSE, control = bbgdm.control())

## S3 method for class 'bbgdm'
print(x, ...)

## S3 method for class 'bbgdm'
plot(x, ...)

## S3 method for class 'bbgdm'
predict(x, data, neighbourhood = NULL, outer = FALSE,
  uncertainty = TRUE, ...)

Arguments

form

formula for bbgdm model

sp.dat

presence absence matrix, sp as columns sites as rows.

env.dat

environmental or spatial covariates at each site.

family

a description of the error distribution and link function to be used in the model. Currently "binomial" suppported. This can be a character string naming a family function, a family function or the result of a call to a family function.

link

a character string that assigns the link function to apply within the binomial model. Default is 'logit', but 'negexp' and other binomial link functions can be called.

dism_metric

dissimilarity metric to calculate for model. "bray_curtis" or "number_non_shared" currently avaliable.

nboot

number of Bayesian Bootstraps to run, this is used to estimate variance around GDM models. Default is 100 iterations.

spline_type

type of spline to use in GDM model. Default is monotonic isplines. Options are: "ispline" or "bspline".

spline_df

Number of spline degrees of freedom.

spline_knots

Number of spline knots.

geo

logical If true geographic distance is calculated if

geo.type

type of geographic distance to estimate, can call 'euclidean' and 'greater_circle'.

coord.names

character.vector names of coordinates, default is c("X","Y")

optim.meth

optimisation method options avaliable are 'optim' and 'nlmnib'

est.var

logical if true estimated parameter variance using optimiser.

trace

logical print extra optimisation outputs

prior

numeric vector of starting values for intercept and splines

control

control options for gdm calls bbgdm.control as default.

x

an object of class bbgdm, constructed by the function bbgdm giving a fitted bbgdm

...

for bbgdm(): one or more plot(), print() and predict(): further arguments passed to or from other methods

data

raster stack of the same covariates used to fit model object for the region you wish to predict too.

neighbourhood

int default is three, number of neighbouring cells to estimate mean dissimilarity.

outer

logical default is FALSE, if TRUE only calculates the outer edge of neighbourhoods area.

uncertainty

logical if TRUE predict will return a list with two rasters the mean estimate and the uncertainty (defined as the coefficent of variation)

Value

a bbgdm model object

raster of mean turnover estimated based on neighbourhood distance.

References

Woolley, S. N., Foster, S. D., O'Hara, T. D., Wintle, B. A., & Dunstan, P. K. (2017). Characterising uncertainty in generalised dissimilarity models. Methods in Ecology and Evolution.

Examples

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## Not run: 
sp.dat <- matrix(rbinom(2000,1,.6),200,10)# presence absence matrix
env.dat <- simulate_covariates(sp.dat,2)
form <- ~ 1 + covar_1 + covar_2
test.bbgdm <- bbgdm(form,sp.dat, env.dat,family="binomial",dism_metric="number_non_shared",
                    nboot=10, geo=FALSE,optim.meth='nlmnib',,control=bbgdm.control(cores=3))

## End(Not run)
#print model summary
## Not run: 
print(test.bbgdm)
## End(Not run)

#plot bbgdm fit
 ## Not run: 
plot(test.bbgdm)
## End(Not run)

skiptoniam/bbgdm documentation built on May 30, 2019, 1:05 a.m.