R: Compares various fitted distributions to censored data on a...

cdfcompcens {fitdistrplus} | R Documentation

## Compares various fitted distributions to censored data on a cdf plot

### Description

Plots the empirical cumulative distribution (censored continuous data) with theoretical ones corresponding to various fitted distributions.

### Usage

    cdfcompcens(ft, xlim, ylim, xlogscale = FALSE, ylogscale = FALSE, main, xlab, ylab,
        datacol, fitlty, fitcol, addlegend = TRUE, legendtext, xlegend = "bottomright",
        ylegend = NULL, lines01 = FALSE, Turnbull.confint = FALSE, add = FALSE, ...)

### Arguments

`ft` | One `"fitdistcens"` object or a list of objects of class `"fitdistcens"`.
`xlim` | The x-limits of the plot.
`ylim` | The y-limits of the plot.
`xlogscale` | If `TRUE`, uses a logarithmic scale for the x-axis.
`ylogscale` | If `TRUE`, uses a logarithmic scale for the y-axis.
`main` | A main title for the plot, see also `title`.
`xlab` | A label for the x-axis, defaults to a description of `x`.
`ylab` | A label for the y-axis, defaults to a description of `y`.
`datacol` | A specification of the color to be used in plotting data points.
`fitcol` | A (vector of) color(s) to plot fitted distributions. If there are fewer colors than fits they are recycled in the standard fashion.
`fitlty` | A (vector of) line type(s) to plot fitted distributions. If there are fewer colors than fits they are recycled in the standard fashion. See also `par`.
`addlegend` | If `TRUE`, a legend is added to the plot.
`legendtext` | A character or expression vector of length ≥q 1 to appear in the legend, see also `legend`.
`xlegend, ylegend` | The x and y co-ordinates to be used to position the legend. They can be specified by keyword or in any way which is accepted by 'xy.coords': see `legend` for details.
`lines01` | A logical to plot two horizontal lines at `h=0` and `h=1`.
`Turnbull.confint` | if TRUE, confidence intervals will be added to the Turnbull plot of the empirical distribution.
`add` | logical; if `TRUE` add to an already existing plot; if `FALSE` start a new plot.
`...` | Further graphical arguments passed to graphical functions used in `cdfcompcens`.

### Details

Empirical and theoretical distributions are plotted in cdf. The EM approach of Turnbull (Turnbull, 1974) is used to compute the overall empirical cdf curve, with confidence intervals if `Turnbull.confint` is `TRUE`, by calls to functions `survfit` and `plot.survfit` from the `survival` package. By default a legend is added to the plot. Many graphical arguments are optional, dedicated to personalize the plot, and fixed to default values if omitted.

### Author(s)

Marie-Laure Delignette-Muller and Christophe Dutang.

### References

Turnbull BW (1974), Nonparametric estimation of a survivorship function with doubly censored data. Journal of American Statistical Association, 69, 169-173.

Delignette-Muller ML and Dutang C (2015), fitdistrplus: An R Package for Fitting Distributions. Journal of Statistical Software, 64(4), 1-34.

### See Also

`CIcdfplot`, `plotdistcens`, `survfit.formula`, `legend` and `par`.

### Examples

    # (1) Plot various distributions fitted to bacterial contamination data
    #
    data(smokedfish)
    Clog10 <- log10(smokedfish)

    fitsfn <- fitdistcens(Clog10,"norm")
    summary(fitsfn)

    fitsfl <- fitdistcens(Clog10,"logis")
    summary(fitsfl)

    dgumbel <- function(x,a,b) 1/b*exp((a-x)/b)*exp(-exp((a-x)/b))
    pgumbel <- function(q,a,b) exp(-exp((a-q)/b))
    qgumbel <- function(p,a,b) a-b*log(-log(p))
    fitsfg<-fitdistcens(Clog10,"gumbel",start=list(a=-3,b=3))
    summary(fitsfg)

    cdfcompcens(list(fitsfn,fitsfl,fitsfg))
    cdfcompcens(list(fitsfn,fitsfl,fitsfg),datacol="orange",
        legendtext=c("normal","logistic","Gumbel"),
        main="bacterial contamination fits",
        xlab="bacterial concentration (CFU/g)",ylab="F",
        xlegend = "center",lines01 = TRUE)

[Package fitdistrplus version 1.0-9 Index]