Performs a nonparametric Wilcoxon signed-rank test of whether the median difference between two columns of paired censored data equals 0. Uses the Pratt adjustment for pairs of equal or indistinguishable values.

cen_signedranktest(xd, xc, yd, yc, alternative = "two.sided", printstat = TRUE)

## Arguments

xd |
The first column of data values plus detection limits |

xc |
The column of censoring indicators for `xd` , where 1 (or `TRUE` ) indicates a detection limit in the xd column, and 0 (or `FALSE` ) indicates a detected value in xd. |

yd |
The second column of data values plus detection limits, or a single number representing a standard / guideline value. |

yc |
The column of censoring indicators for yd, where 1 (or `TRUE` ) indicates a detection limit in the yd column, and 0 (or `FALSE` ) indicates a detected value in `yd` . Not needed if `yd` is a single standard number. |

alternative |
The usual notation for the alternate hypothesis. Default is `“two.sided”` . Options are `“greater”` or `“less”` . |

printstat |
Logical `TRUE` /`FALSE` option of whether to print the resulting statistics in the console window, or not. Default is `TRUE.` |

## Value

Prints a list of Wilcoxon Signed-Rank test with Pratt correction for ties statistics containing the following components:

## References

Helsel, D.R., 2011. Statistics for censored environmental data using Minitab and R, 2nd ed. John Wiley & Sons, USA, N.J.

Page, E.B., 1963. Ordered Hypotheses for Multiple Treatments: A Significance Test for Linear Ranks. Journal of the American Statistical Association 58, 216–230. doi: 10.2307/2282965

Pratt, J.W., 1959. Remarks on Zeros and Ties in the Wilcoxon Signed Rank Procedures. Journal of the American Statistical Association 54, 655–667. doi: 10.2307/2282543

## Examples

#> Censored signed-rank test for (x:atrazine$June - y:atrazine$Sept) equals 0
#> alternative hypothesis: true difference atrazine$June - atrazine$Sept does not equal 0
#>
#> Pratt correction for ties
#> n = 24, Z = -3.319, p.value = 0.0009033