COforest: Colorado Forest Data Set

In cgam: Constrained Generalized Additive Model

Colorado Forest Data Set

Description

This data set contains 9167 records of different species of live trees for 345 sampled forested plots measured in 2015.

Usage

data("COforest")

Format

A data frame with 9167 observations on the following 19 variables.

PLT_CN

Unique identifier of plot

STATECD

State code using Bureau of Census Federal Information Processing Standards (FIPS)

COUNTYCD

County code (FIPS)

ELEV_PUBLIC

Elevation (ft) extracted spatially using LON_PUBLIC/LAT_PUBLIC

LON_PUBLIC

Fuzzed longitude in decimal degrees using NAD83 datum

LAT_PUBLIC

Fuzzed latitude in decimal degrees using NAD83 datum

ASPECT

a numeric vector

SLOPE

a numeric vector

SUBP

Subplot number

TREE

Tree number within subplot

STATUSCD

Tree status (0:no status; 1:live tree; 2:dead tree; 3:removed)

SPCD

Species code

DIA

Current diameter (in)

HT

Total height (ft): estimated when broken or missing

ACTUALHT

Actual height (ft): measured standing or down

HTCD

Height method code (1:measured; 2:actual measured-length estimated; 3:actual and length estimated; 4:modeled

TREECLCD

Tree class code (2:growing-stock; 3:rough cull; 4:rotten cull)

CR

Compacted crown ratio (percentage)

CCLCD

Crown class (1:open grown; 2:domimant; 3:co-dominant; 4:intermediate; 5:overtopped)

Source

It is provided by Forest Inventory Analysis (FIA) National Program.

References

X. Liao and M. Meyer (2019). Estimation and Inference in Mixed-Effect Regression Models using Shape Constraints, with Application to Tree Height Estimation. (to appear in Journal of the Royal Statistical Society. Series C: Applied Statistics)

Examples

## Not run: 
  library(dplyr)
  library(tidyr)
  data(COforest)

  #re-grouping classes of CCLCD:
  #combine dominant (2) and co-dominant (3)
  #combine intermediate (4) and overtopped (5)
  COforest = COforest 
    mutate(CCLCD = replace(CCLCD, CCLCD == 5, 4))

  #make a list of species, each element is a small data frame for one species
  species = COforest 

  #get the subset for quaking aspen, which is the 4th element in the species list
  sub = species$data[[4]]
  #for quaking aspen, there are only two crown classes: dominant/co-dominant
  #and intermediate/overtopped
  table(sub$CCLCD)
  #   3    4
  #1400  217
  #for quaking aspen, there are only two tree clases: growing-stock and rough cull
  table(sub$TREECLCD)
  #2    3
  #1591   26

  #fit the model
  ansc = cgamm(log(HT)~s.incr.conc(DIA)+factor(CCLCD)+factor(TREECLCD)
  +(1|PLT_CN), reml=TRUE, data=sub)

  #check which classes are significant
  summary(ansc)

  #fixed-effect 95
  newData = data.frame(DIA=sub$DIA,CCLCD=sub$CCLCD,TREECLCD=sub$TREECLCD)
  pfit = predict(ansc, newData,interval='confidence')
  lower = pfit$lower
  upper = pfit$upper
  #we need to use exp(muhat) later in the plot
  muhat = pfit$fit

  #get x and y
  x = sub$DIA
  y = sub$HT

  #get TREECLCD and CCLCD
  z1 = sub$TREECLCD
  z2 = sub$CCLCD

  #plot fixed-effect confidence intervals
  plot(x, y, xlab='DIA (m)', ylab='HT (m)', ylim=c(min(y),max(exp(upper))+10),type='n')
  lines(sort(x[z2==3&z1==2]), (exp(pfit$fit)[z2==3&z1==2])[order(x[z2==3&z1==2])],
  col='slategrey', lty=1, lwd=2)
  lines(sort(x[z2==3&z1==2]), (exp(pfit$lower)[z2==3&z1==2])[order(x[z2==3&z1==2])],
  col='slategrey', lty=1, lwd=2)
  lines(sort(x[z2==3&z1==2]), (exp(pfit$upper)[z2==3&z1==2])[order(x[z2==3&z1==2])],
  col='slategrey', lty=1, lwd=2)

  lines(sort(x[z2==4&z1==2]), (exp(pfit$fit)[z2==4&z1==2])[order(x[z2==4&z1==2])],
  col="blueviolet", lty=2, lwd=2)
  lines(sort(x[z2==4&z1==2]), (exp(pfit$lower)[z2==4&z1==2])[order(x[z2==4&z1==2])],
  col="blueviolet", lty=2, lwd=2)
  lines(sort(x[Cz2==4&z1==2]), (exp(pfit$upper)[Cz2==4&z1==2])[order(x[Cz2==4&z1==2])],
  col="blueviolet", lty=2, lwd=2)

  lines(sort(x[Cz2==3&z1==3]), (exp(pfit$fit)[Cz2==3&z1==3])[order(x[Cz2==3&z1==3])],
  col=3, lty=3, lwd=2)
  lines(sort(x[Cz2==3&z1==3]), (exp(pfit$lower)[Cz2==3&z1==3])[order(x[Cz2==3&z1==3])],
  col=3, lty=3, lwd=2)
  lines(sort(x[Cz2==3&z1==3]), (exp(pfit$upper)[Cz2==3&z1==3])[order(x[Cz2==3&z1==3])],
  col=3, lty=3, lwd=2)

  lines(sort(x[Cz2==4&z1==3]), (exp(pfit$fit)[Cz2==4&z1==3])[order(x[Cz2==4&z1==3])],
  col=2, lty=4, lwd=2)
  lines(sort(x[Cz2==4&z1==3]), (exp(pfit$lower)[Cz2==4&z1==3])[order(x[Cz2==4&z1==3])],
  col=2, lty=4, lwd=2)
  lines(sort(x[Cz2==4&z1==3]), (exp(pfit$upper)[Cz2==4&z1==3])[order(x[Cz2==4&z1==3])],
  col=2, lty=4, lwd=2)
  legend('bottomright', bty='n', cex=.9,c('dominant/co-dominant and growing stock',
  'intermediate/overtopped and growing stock','dominant/co-dominant and rough cull',
  'intermediate/overtopped and rough cull'), col=c('slategrey',"blueviolet",3,2),
  lty=c(1,2,3,4),lwd=c(2,2,2,2), pch=c(24,23,22,21))
  title('Quaking Aspen fits with 95

## End(Not run)

cgam documentation built on June 8, 2025, 1:45 p.m.