Learn R Programming

siland (version 1.4.6)

Fsiland: Estimation of landscape influence with spatial influnce functions

Description

Fsiland is used to fit spatial influence of landscape.

Usage

Fsiland(formula,land,data,family ="gaussian",sif="exponential", init = 100,
 border=F,wd=50)

Arguments

formula

a symbolic description (see lm() or glm()) of the response variable concerning local variables. Random effects are also allowed according to the syntax in package lme4 (see lmer() function in package lme4).

land

an object of class sf that gives the landscape variables for the model

data

a dataframe containing the response variable and the local variables.

family

the distribution of response variable. family can be "gaussian", "poisson" or "binomial" and the associated link function are identity, log and logit respectively.

sif

the family of the spatial influence function. sif can be "exponential" or "gaussian".

init

a vector indicating the starting values for the estimation of the mean distance of the spatial influence functions. If one value is given, parameter for each spatial influnce function are initialised with this value. By default, initialisation is equal to 100 for each landscape variable.

border

a logical indicating if pixels into the field (polygon) where obervations are located have to be take into account to evaluate the influences. If border=T (by default), all pixels are take into accpount. If Border=F, only pixels outside the fiels (polygon) are condidered to evaluate influnce for landscape variables.

wd

a number indiacting the size of pixels for raster discretisazion.

Value

Fsiland returns an object of type list.

coefficients

vector of estimated coefficients

paramSIF

vector of estimated coefficients

formula

an object of class formula that indicates the local model used

landcontri

a dataframe of estimated contributions of each spatial variable (in column) to each observation (in row). The number of columns is equal to the length of list land

loglik

log-likelihood for the model

loglik0

log-likelihood for the local model (only local variables)

result

an object of type lm/glm/lmer that corresponds to the estimated model conditionnaly to the estimated influence functions.

fitted

fitted values

sif

the family of the spatial influence function

resoptim

an object of class optim or optimize giving informations about the optimization procedure see optim() or optimize() for further details.

AIC

akaike information criterion

AIC0

akaike information criterion for local model (no landscape variable)

nparam

number of parameters

pval0

p.value of the test of global effect of spatial variables. Obtained from the likelihood ratio test between the complete model and the local model.

family

family distribution for the model

sd.error

standard error for gaussian family, NA in other case

model.Type

type of local model: GLM for generalised model, LMM for linear mixed model or GLMM for generalised linear mixed model

rand.StdDev

standard deviation of random effects for LMM or GLMM

err

estimated residuals

border

a logical indicating the value used for estimation

wd

a number indicating the value used for raster discretisazion

References

Chandler R. and Hepinstall-Cymerman J. (2016) Estimating the spatial scales of landscape effects on abundance. Landscape ecology, 31: 1383-1394.

Examples

Run this code
# NOT RUN {
data(dataSiland)
data(landSiland)
resF=Fsiland(y~locvar,land=landSiland,data=dataSiland,sif="exponential")
resF
resF$AIC
# }
# NOT RUN {
# }

Run the code above in your browser using DataLab