Introduction to the multiocc package

library(interp)
library(MCMCpack)
#> Loading required package: coda
#> Loading required package: MASS
#> 
#> Attaching package: 'MASS'
#> The following object is masked from 'package:interp':
#> 
#>     area
#> ##
#> ## Markov Chain Monte Carlo Package (MCMCpack)
#> ## Copyright (C) 2003-2026 Andrew D. Martin, Kevin M. Quinn, and Jong Hee Park
#> ##
#> ## Support provided by the U.S. National Science Foundation
#> ## (Grants SES-0350646 and SES-0350613)
#> ##
library(tmvtnorm)
#> Loading required package: mvtnorm
#> Loading required package: Matrix
#> Loading required package: stats4
#> Loading required package: gmm
#> Loading required package: sandwich
library(truncnorm)
library(multiocc)
library(MASS)
library(corrplot)
#> corrplot 0.95 loaded
library(fields)
#> Loading required package: spam
#> Spam version 2.11-4 (2026-05-28) is loaded.
#> Type 'help( Spam)' or 'demo( spam)' for a short introduction 
#> and overview of this package.
#> Help for individual functions is also obtained by adding the
#> suffix '.spam' to the function name, e.g. 'help( chol.spam)'.
#> 
#> Attaching package: 'spam'
#> The following object is masked from 'package:stats4':
#> 
#>     mle
#> The following object is masked from 'package:Matrix':
#> 
#>     det
#> The following objects are masked from 'package:mvtnorm':
#> 
#>     rmvnorm, rmvt
#> The following objects are masked from 'package:base':
#> 
#>     backsolve, forwardsolve
#> Loading required package: viridisLite
#> Loading required package: RColorBrewer
#> 
#> Try help(fields) to get started.
data(detection)
data(occupancy)
data(coords)
DataNames <- list("species"=colnames(detection)[4:9],
             "detection"=c("duration"),"occupancy"=c("forest","elev"))
model.input <- multioccbuild(detection, occupancy, coords, DataNames, threshold = 15000)
#> Warning: Rows in detection with missing covariates have been removed for purposes of fitting the model, but the site/season combination is retained in occupancy and therefore predictions will be outputted.

Perform some exploratory data analysis

par(mfrow=c(1,3))
hist(occupancy$forest, main="", xlab="Forest")
hist(occupancy$elev, main="", xlab="Elevation")
hist(detection$duration, main="", xlab="Duration")


par(mfrow=c(3,2), mar=c(3,3,3,1))
quilt.plot(coords[,2:3], occupancy$forest[1:267], main="Forest Cover", zlim=c(-1.5,3))
fit <- Tps(coords[,2:3], occupancy$forest[1:267])
out <- predictSurface(fit, df=100)
image.plot(out, main="Forest Cover (interpolated)", zlim=c(-1.5,2))

quilt.plot(coords[,2:3], occupancy$elev[1:267], main="Elevation", zlim=c(-1.5,3.5))
fit <- Tps(coords[,2:3], occupancy$elev[1:267])
out <- predictSurface(fit, df=100)
image.plot(out, main="Elevation (interpolated)", zlim=c(-1.5,2))

quilt.plot(coords[,2:3], detection$duration[1:267], main="Duration", zlim=c(-2.5,3))
fit <- Tps(coords[,2:3], detection$duration[1:267])
out <- predictSurface(fit, df=100)
image.plot(out, main="Duration (Survey 1)", zlim=c(-2.5,2.5))

A short run for demonstration purposes

## Shorter run for demonstration purposes.
## library(tmvtnorm)
mcmc.out <- GibbsSampler(M.iter=10, M.burn=1, M.thin=1, model.input, q=10, sv=FALSE)
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A longer run (not executed) for scientific results

mcmc.out <- GibbsSampler(M.iter=50000, M.burn=20000, M.thin=1, model.input, q=10, sv=FALSE)

Can summarize output

summary(mcmc.out$samples$alpha)
#> 
#> Iterations = 1:9
#> Thinning interval = 1 
#> Number of chains = 1 
#> Sample size per chain = 9 
#> 
#> 1. Empirical mean and standard deviation for each variable,
#>    plus standard error of the mean:
#> 
#>                         Mean      SD Naive SE Time-series SE
#> Great.tit Int       0.713007 0.07197 0.023991       0.046799
#> Great.tit forest   -0.112864 0.03747 0.012489       0.025531
#> Great.tit elev     -0.182750 0.02600 0.008666       0.008666
#> Blue.tit Int        0.459333 0.06138 0.020459       0.043076
#> Blue.tit forest    -0.114337 0.04538 0.015127       0.015127
#> Blue.tit elev      -0.167298 0.03661 0.012204       0.012204
#> Coal.tit Int        0.843922 0.11017 0.036723       0.069351
#> Coal.tit forest     0.047039 0.01344 0.004478       0.002778
#> Coal.tit elev      -0.078690 0.03501 0.011669       0.024495
#> Crested.tit Int     0.555141 0.11395 0.037983       0.074773
#> Crested.tit forest  0.008411 0.01333 0.004444       0.004444
#> Crested.tit elev   -0.112999 0.02480 0.008267       0.008267
#> Marsh.tit Int       0.304017 0.12228 0.040759       0.094867
#> Marsh.tit forest   -0.139085 0.03373 0.011243       0.021937
#> Marsh.tit elev     -0.148862 0.02989 0.009962       0.009962
#> Willow.tit Int      0.158287 0.08081 0.026937       0.050971
#> Willow.tit forest   0.095235 0.03085 0.010283       0.013375
#> Willow.tit elev     0.071009 0.03489 0.011631       0.020506
#> 
#> 2. Quantiles for each variable:
#> 
#>                        2.5%       25%      50%      75%    97.5%
#> Great.tit Int       0.57786  0.690634  0.72883  0.75181  0.78604
#> Great.tit forest   -0.18151 -0.129893 -0.08658 -0.08516 -0.08428
#> Great.tit elev     -0.21705 -0.199097 -0.18684 -0.16828 -0.13938
#> Blue.tit Int        0.35220  0.422162  0.47817  0.50766  0.51569
#> Blue.tit forest    -0.18321 -0.122868 -0.11678 -0.09827 -0.03970
#> Blue.tit elev      -0.20490 -0.192683 -0.16438 -0.15909 -0.09786
#> Coal.tit Int        0.63107  0.837738  0.88874  0.89382  0.93607
#> Coal.tit forest     0.02923  0.040227  0.04492  0.05094  0.07133
#> Coal.tit elev      -0.12202 -0.099300 -0.08961 -0.05570 -0.02682
#> Crested.tit Int     0.34779  0.499882  0.59500  0.63145  0.66915
#> Crested.tit forest -0.01220 -0.003127  0.01376  0.01607  0.02597
#> Crested.tit elev   -0.15500 -0.120830 -0.11763 -0.08834 -0.08377
#> Marsh.tit Int       0.10603  0.232507  0.35158  0.38287  0.45381
#> Marsh.tit forest   -0.18329 -0.163466 -0.13848 -0.12029 -0.08857
#> Marsh.tit elev     -0.17918 -0.169275 -0.15662 -0.12857 -0.09647
#> Willow.tit Int      0.01273  0.131715  0.18980  0.20260  0.24984
#> Willow.tit forest   0.04755  0.076114  0.10243  0.12042  0.13065
#> Willow.tit elev     0.02590  0.047114  0.06032  0.08772  0.12232
summary(mcmc.out$samples$rho)
#> 
#> Iterations = 1:9
#> Thinning interval = 1 
#> Number of chains = 1 
#> Sample size per chain = 9 
#> 
#> 1. Empirical mean and standard deviation for each variable,
#>    plus standard error of the mean:
#> 
#>                   Mean      SD Naive SE Time-series SE
#> Great.tit rho   0.7350 0.12641  0.04214        0.08303
#> Blue.tit rho    0.6582 0.17365  0.05788        0.13847
#> Coal.tit rho    0.7161 0.11269  0.03756        0.08534
#> Crested.tit rho 0.7719 0.13658  0.04553        0.08870
#> Marsh.tit rho   0.7789 0.12705  0.04235        0.08203
#> Willow.tit rho  0.9257 0.04507  0.01502        0.02977
#> 
#> 2. Quantiles for each variable:
#> 
#>                   2.5%    25%    50%    75%  97.5%
#> Great.tit rho   0.5589 0.6756 0.6994 0.8402 0.9081
#> Blue.tit rho    0.3990 0.5314 0.6569 0.7641 0.8773
#> Coal.tit rho    0.5571 0.6297 0.7430 0.8266 0.8362
#> Crested.tit rho 0.5452 0.7497 0.7981 0.8472 0.9308
#> Marsh.tit rho   0.5622 0.7414 0.8205 0.8228 0.9400
#> Willow.tit rho  0.8573 0.8937 0.9172 0.9648 0.9841

Visualize correlation matrix

par(mfrow=c(1,1), mar=c(3,3,3,1))
sigout <- mcmc.out$samples$sig
Sig <- matrix(colMeans(sigout),6,6)
SpeciesCor <- cov2cor(Sig)
rownames(SpeciesCor) <- DataNames$species
colnames(SpeciesCor) <- DataNames$species
corrplot::corrplot(SpeciesCor)

Make predictions from fitted model

y.agg1 <-  aggregate(model.input$y[,1], by=list(model.input$detection.info$siteID, 
                                              model.input$detection.info$season), FUN=sum, na.rm=TRUE)
y.plot1 <- 1*(y.agg1$x>0)

y.agg2 <- aggregate(model.input$y[,2], by=list(model.input$detection.info$siteID, 
                                              model.input$detection.info$season), FUN=sum, na.rm=TRUE)
y.plot2 <- 1*(y.agg2$x>0)

y.agg3 <- aggregate(model.input$y[,3], by=list(model.input$detection.info$siteID, 
                                              model.input$detection.info$season), FUN=sum, na.rm=TRUE)
y.plot3 <- 1*(y.agg3$x>0)

y.agg4 <- aggregate(model.input$y[,4], by=list(model.input$detection.info$siteID, 
                                              model.input$detection.info$season), FUN=sum, na.rm=TRUE)
y.plot4 <- 1*(y.agg4$x>0)

y.agg5 <- aggregate(model.input$y[,5], by=list(model.input$detection.info$siteID, 
                                              model.input$detection.info$season), FUN=sum, na.rm=TRUE)
y.plot5 <- 1*(y.agg5$x>0)

y.agg6 <- aggregate(model.input$y[,6], by=list(model.input$detection.info$siteID, 
                                              model.input$detection.info$season), FUN=sum, na.rm=TRUE)
y.plot6 <- 1*(y.agg6$x>0)

for (yr in c(1,4,7,10)){
  print(yr)

  range <- which(model.input$occupancy.info$season == yr)

  psiout <- mcmc.out$samples$psi
  #pout <- mcmc.out$p
  dim(psiout)

  psi1 <- apply(psiout[,0*2670+range],2,mean)
  psi2 <- apply(psiout[,1*2670+range],2,mean)
  psi3 <- apply(psiout[,2*2670+range],2,mean)
  psi4 <- apply(psiout[,3*2670+range],2,mean)
  psi5 <- apply(psiout[,4*2670+range],2,mean)
  psi6 <- apply(psiout[,5*2670+range],2,mean)

  par(mfrow=c(3,2), mar=c(1,3,3,1))
  fit <- Tps(coords[1:267,2:3], psi1)
  out <- predictSurface(fit, df=100)
  image.plot(out, main="Great Tit", zlim=c(-0.01,1.01))
  mtext(paste("Year",yr), side=3, line=-2, outer=TRUE)

  y.plot1.in <- y.plot1[which(model.input$occupancy.info$season ==yr)]
  points(coords[which(y.plot1.in==1),2:3])

  fit <- Tps(coords[1:267,2:3], psi2)
  out <- predictSurface(fit, df=100)
  image.plot(out, main="Blue Tit", zlim=c(-0.01,1.01))

  y.plot2.in <- y.plot2[which(model.input$occupancy.info$season ==yr)]
  points(coords[which(y.plot2.in==1),2:3])

  fit <- Tps(coords[1:267,2:3], psi3)
  out <- predictSurface(fit, df=100)
  image.plot(out, main="Coal Tit", zlim=c(-0.01,1.01))

  y.plot3.in <- y.plot3[which(model.input$occupancy.info$season ==yr)]
  points(coords[which(y.plot3.in==1),2:3])

  fit <- Tps(coords[1:267,2:3], psi4)
  out <- predictSurface(fit, df=100)
  image.plot(out, main="Crested Tit", zlim=c(-0.01,1.01))

  y.plot4.in <- y.plot4[which(model.input$occupancy.info$season ==yr)]
  points(coords[which(y.plot4.in==1),2:3])

  fit <- Tps(coords[1:267,2:3], psi5)
  out <- predictSurface(fit, df=100)
  image.plot(out, main="Marsh Tit", zlim=c(-0.01,1.01))

  y.plot5.in <- y.plot5[which(model.input$occupancy.info$season ==yr)]
  points(coords[which(y.plot5.in==1),2:3])

  fit <- Tps(coords[1:267,2:3], psi6)
  out <- predictSurface(fit, df=100)
  image.plot(out, main="Willow Tit", zlim=c(-0.01,1.01))

  y.plot6.in <- y.plot6[which(model.input$occupancy.info$season ==yr)]
  points(coords[which(y.plot6.in==1),2:3])
}
#> [1] 1

#> [1] 4

#> [1] 7

#> [1] 10