poly5Model {rForest} | R Documentation |
poly5Model is used to fit a fifth-degree polynomial taper model
poly5Model(dbh,ht,di,hi, plotxy)
dbh, |
vector of diameter at breast height |
ht, |
vector of measured tree heights |
di, |
vector of measured tree diameters at i heights |
hi, |
vector of measured tree i heights |
plotxy, |
plot the fitted model |
Returns a fifth-degree polynomial taper model as an object of class "lm"
Carlos A. Silva, Samuel P. C. Carvalho, Carine Klauberg Silva and Manoela de O. Rosa
Schoepfer (1966) model :fifth-degree polynomial taper model
di/dbh= (hi/ht) + (hi/ht)^2 + (hi/ht)^3 + (hi/ht)^4 + (hi/ht)^5
# Importing forest inventory data data(ForestInv01) # setting model parametersdbh and ht hi<-ForestInv01[,2] di<-ForestInv01[,3] ht<-ForestInv01[,4] dbh<-ForestInv01[,5] # fitting the fifth-degree polynomial taper model fit <- poly5Model(dbh,ht,di,hi, plotxy=TRUE) #grid()