In Silviculturalist/forester: Forest Science and Forestry

knitr::opts_chunk$set(echo = TRUE)

Hoffmann, C. 1982. Die Berechnung von Tarifen für die Waldinventur. Reports. 236. Swiss Federal Institute of Forestry Research. CH-8903 Birmensdorf. Sonderdruck aus Forstwissenschaftliches Centralblatt 101 (1982), 1:24-36. Available Online (14th June 2022):

Data.

library(tidyverse)
library(forester)

data("Hoffmann_1982") #Included with forester package.

colnames(Hoffmann_1982) <- c("Diameter_cm","Volume")

# nls(Volume~exp(a1)*(Diameter_cm^a2)*exp(a3*log(Diameter_cm)^4),data = Hoffmann_1982,start = c(a1=-3,a2=3,a3=-0.05))


Hoffmann_1982 %>% ggplot(aes(x=Diameter_cm,y=Volume))+
  labs(y=expression(Volume~m^3),
         x=expression(Diameter~at~breast~height~"(cm)"))+
  scale_x_continuous(trans="log",lim=c(0.01,100),breaks=c(5,10,20,30,40,50,70,100))+
  scale_y_continuous(trans="log",lim=c(0.01,10),breaks=c(0.02,0.03,0.05,0.1,0.2,0.3,0.5,1,2,3,5,7))+
  geom_point()+
  coord_cartesian(xlim=c(5,100),ylim=c(0.02,9))+
  geom_function(fun= function(x) exp(-9.687304) * (x^2.981208) * exp(-0.004043 * log(x)^4))+
  theme_classic()

Silviculturalist/forester documentation built on April 20, 2024, 2:13 p.m.