Last data update: 2014.03.03

R: The 'DirichletReg' Package
DirichletReg-packageR Documentation

The DirichletReg Package

Description

This package provides a functions to analyze compositional data using Dirichlet regression methods.

Package:DirichletReg
Type: Package
Version:Sexpr[stage=build]{packageDescription("DirichletReg")$Version}
Date: Sexpr[stage=build]{packageDescription("DirichletReg")$Date}
License:Sexpr[stage=build]{packageDescription("DirichletReg")$License}

Author(s)

Marco J. Maier

Examples

  example(plot.DirichletRegData)
  example(DirichReg)

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(DirichletReg)
Loading required package: Formula
Loading required package: rgl
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/DirichletReg/DirichletReg-package.Rd_%03d_medium.png", width=480, height=480)
> ### Name: DirichletReg-package
> ### Title: The 'DirichletReg' Package
> ### Aliases: DirichletReg DirichletReg
> ### Keywords: package
> 
> ### ** Examples
> 
>   example(plot.DirichletRegData)

pl.DRD> # plot of "Sand" in the Arctic Lake data set
pl.DRD> plot(DR_data(ReadingSkills[, 1]), main="Reading Accuracy")
only one variable in [0, 1] supplied - beta-distribution assumed.
check this assumption.

pl.DRD> # ternary plot of Arctic Lake data
pl.DRD> plot(DR_data(ArcticLake[, 1:3]), a2d = list(colored = FALSE))
Warning in DR_data(ArcticLake[, 1:3]) :
  not all rows sum up to 1 => normalization forced
>   example(DirichReg)

DrchRg> ALake <- ArcticLake

DrchRg> ALake$Y <- DR_data(ALake[,1:3])
Warning in DR_data(ALake[, 1:3]) :
  not all rows sum up to 1 => normalization forced

DrchRg> # fit a quadratic Dirichlet regression models ("common")
DrchRg> res1 <- DirichReg(Y ~ depth + I(depth^2), ALake)

DrchRg> # fit a Dirichlet regression with quadratic predictor for the mean and
DrchRg> # a linear predictor for precision ("alternative")
DrchRg> res2 <- DirichReg(Y ~ depth + I(depth^2) | depth, ALake, model="alternative")

DrchRg> # test both models
DrchRg> anova(res1, res2)
Analysis of Deviance Table

Model 1: DirichReg(formula = Y ~ depth + I(depth^2), data = ALake)
Model 2: DirichReg(formula = Y ~ depth + I(depth^2) | depth, data = ALake,
  model = "alternative")

        Deviance N. par Difference df Pr(>Chi)
Model 1  -217.99      9                       
Model 2  -215.68      8     2.3136  1   0.1282


DrchRg> res1
Call:
DirichReg(formula = Y ~ depth + I(depth^2), data = ALake)
using the common parametrization

Log-likelihood: 109 on 9 df (162 BFGS + 2 NR Iterations)

-----------------------------------------
Coefficients for variable no. 1: sand
(Intercept)        depth   I(depth^2)  
  1.4361967   -0.0072382    0.0001324  
-----------------------------------------
Coefficients for variable no. 2: silt
(Intercept)        depth   I(depth^2)  
 -0.0259705    0.0717450   -0.0002679  
-----------------------------------------
Coefficients for variable no. 3: clay
(Intercept)        depth   I(depth^2)  
 -1.7931487    0.1107906   -0.0004872  
-----------------------------------------

DrchRg> summary(res2)
Call:
DirichReg(formula = Y ~ depth + I(depth^2) | depth, data = ALake, model =
"alternative")

Standardized Residuals:
          Min       1Q   Median      3Q     Max
sand  -1.7598  -0.7459  -0.1833  1.0148  2.7250
silt  -1.1459  -0.5379  -0.1581  0.2467  1.5572
clay  -1.9269  -0.6106  -0.0617  0.6294  1.9976

MEAN MODELS:
------------------------------------------------------------------
Coefficients for variable no. 1: sand
- variable omitted (reference category) -
------------------------------------------------------------------
Coefficients for variable no. 2: silt
              Estimate Std. Error z value Pr(>|z|)    
(Intercept) -1.2885187  0.3835030  -3.360  0.00078 ***
depth        0.0706992  0.0147385   4.797 1.61e-06 ***
I(depth^2)  -0.0003247  0.0001210  -2.684  0.00727 ** 
------------------------------------------------------------------
Coefficients for variable no. 3: clay
              Estimate Std. Error z value Pr(>|z|)    
(Intercept) -2.9754613  0.4973405  -5.983 2.19e-09 ***
depth        0.1064013  0.0180002   5.911 3.40e-09 ***
I(depth^2)  -0.0005161  0.0001429  -3.612 0.000303 ***
------------------------------------------------------------------

PRECISION MODEL:
------------------------------------------------------------------
            Estimate Std. Error z value Pr(>|z|)    
(Intercept) 1.324382   0.357461   3.705 0.000211 ***
depth       0.041773   0.006604   6.325 2.53e-10 ***
------------------------------------------------------------------
Significance codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Log-likelihood: 107.8 on 8 df (96 BFGS + 2 NR Iterations)
AIC: -199.7, BIC: -186.4
Number of Observations: 39
Links: Logit (Means) and Log (Precision)
Parametrization: alternative
> 
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> 
> dev.off()
null device 
          1 
>