tests/t-fitdistcens.R

In fitdistrplus: Help to Fit of a Parametric Distribution to Non-Censored or Censored Data

library(fitdistrplus)

nsample <- 500
nsample <- 10
visualize <- FALSE # TRUE for manual tests with visualization of results
set.seed(1234)

# (6) custom optimisation function - example with the genetic algorithm
#
data(fluazinam)
log10EC50 <-log10(fluazinam)

  #wrap genoud function rgenoud package
  mygenoud  <-  function(fn, par, ...) 
  {
    require(rgenoud)
    res  <-  genoud(fn, starting.values=par, ...)        
    standardres  <-  c(res, convergence=0)
    
    return(standardres)
  }
  
  # call fitdistcens with a 'custom' optimization function
  fit.with.genoud <- fitdistcens(log10EC50, "logis", custom.optim=mygenoud, nvars=2, 
                                 start=list(location=0, scale=1),    
                                 Domains=cbind(c(0,0), c(5, 5)), boundary.enforcement=1, 
                                 print.level=1, hessian=TRUE)
  
  summary(fit.with.genoud)


# (9) check keepdata
#
if (visualize) # LONG TO RUN ON CRAN AND NEEDS VISALIZATION OF RESULTS
{
  set.seed(1234)
  x <- rexp(1e3, 5)
  # x <- data.frame(left=x, right=x+rexp(x, 1/2))
  x <- data.frame(left=x, right=x)
  f1 <- fitdistcens(x, "exp", keepdata=FALSE)
  f2 <- fitdistcens(x, "exp", keepdata=TRUE)
  f1$censdata
  f2$censdata
  plot(f1)
  plot(f2)
  
}


# (9) fixing parameters
#
x <- rexp(nsample, 5)
x <- data.frame(left=x, right=x+.1)

f1 <- fitdistcens(x, "gamma", fix.arg=list(shape=1.5))
f1
f1$fix.arg

f1 <- fitdistcens(x, "gamma", fix.arg=function(x) list(shape=1.5))
f1
f1$fix.arg.fun


# (10) weights
#
data(salinity)
salinity.unique <- unique(salinity)
string.unique <- paste(salinity.unique$left, salinity.unique$right)
string.salinity <- paste(salinity$left, salinity$right)
nobs <- nrow(salinity.unique)
salinity.weights <- numeric(nobs)
for (i in 1:nobs)
{
  salinity.weights[i] <- length(which(string.salinity == string.unique[i]))
}
cbind(salinity.unique, salinity.weights)

(fa <- fitdistcens(salinity, "lnorm"))
(fb <- fitdistcens(salinity.unique, "lnorm", weights = salinity.weights)) # should give the same results

# (11) check the warning messages when using weights in the fit followed by functions
# that do not yet take weights into account
# with an example to be used later to see if weights are well taken into account
#
x <- rexp(100, 5)
x <- sort(x)
x <- data.frame(left=x, right=x+.1)
(f <- fitdistcens(x, "gamma", weights=c(rep(10, 50), rep(1, 50))))
try(plot(f))
try(cdfcompcens(f))
(f2 <- fitdistcens(x, "weibull", weights=c(rep(10, 50), rep(1, 50))))
try(cdfcompcens(list(f, f2)))
try(bootdistcens(f))