| Type: | Package |
| Title: | Computation of the p-Value for the Exact Conditional Cochran-Armitage Trend Test |
| Version: | 0.1.1 |
| Description: | Provides functions for computing the one-sided p-values of the Cochran-Armitage trend test statistic for the asymptotic and the exact conditional test. The computation of the p-value for the exact test is performed using an algorithm following an idea by Mehta, et al. (1992) <doi:10.2307/1390598>. |
| Depends: | R (≥ 3.6.0) |
| License: | GPL-2 | GPL-3 |
| LazyData: | TRUE |
| RoxygenNote: | 7.0.2 |
| Suggests: | testthat |
| NeedsCompilation: | no |
| Packaged: | 2020-06-25 13:26:34 UTC; edelmand |
| Author: | Dominic Edelmann [aut, cre] |
| Maintainer: | Dominic Edelmann <dominic.edelmann@dkfz-heidelberg.de> |
| Repository: | CRAN |
| Date/Publication: | 2020-06-25 15:40:14 UTC |
Asymptotic Cochran-Armitage trend test
Description
catt_asy calculates the Cochran-Armitage trend test statistic (Cochran (1954), Armitage (1955)) and the one-sided p-value for the corresponding asymptotic test.
The exact form of used test statistic can be found in the paper by Portier and Hoel (1984).
Usage
catt_asy(dose.ratings, totals, cases)
Arguments
dose.ratings |
A vector of dose ratings, the i-th entry corresponds to the dose-rating of the i-th group. This vector must be strictly monotonically increasing |
totals |
The vector of total individuals per group, the i-th entry corresponds to the total number of individuals in the i-th group |
cases |
The vector of incidences per groups, the i-th entry corresponds to the number of incidences in the i-th group |
Value
A list containing the value of the Cochran-Armitage Trend Test Statistic and its asymptotic p-value.
References
Armitage, P. Tests for linear trends in proportions and frequencies. Biometrics, 11 (1955): 375-386.
Cochran, W. G. Some methods for strengthening the common \chi^2 tests, Biometrics. 10 (1954): 417-451.
Portier, C., and Hoel D. Type 1 error of trend tests in proportions and the design of cancer screens. Communications in Statistics-Theory and Methods, 13 (1984): 1-14.
Examples
d <- c(1,2,3,4)
n <- rep(20,4)
r <- c(1,4,3,8)
catt_asy(d, n, r)
Conditional exact Cochran-Armitage trend test
Description
catt_exact calculates the Cochran-Armitage trend test statistic (Cochran (1954), Armitage (1955)) and the one-sided p-value for the corresponding conditional exact test.
The conditional exact test has been established by Williams (1988). The computation of its p-value is performed using an algorithm following an idea by Mehta, et al. (1992).
Usage
catt_exact(dose.ratings, totals, cases)
Arguments
dose.ratings |
A vector of dose ratings, the i-th entry corresponds to the dose-rating of the i-th group. This vector must be strictly monotonically increasing |
totals |
The vector of total individuals per group, the i-th entry corresponds to the total number of individuals in the i-th group. |
cases |
The vector of incidences per groups, the i-th entry corresponds to the number of incidences in the i-th group. |
Value
A list containing the value of the Cochran-Armitage Trend Test Statistic, its exact and asymptotic p-value.
References
Armitage, P. Tests for linear trends in proportions and frequencies. Biometrics, 11 (1955): 375-386.
Cochran, W. G. Some methods for strengthening the common \chi^2 tests, Biometrics. 10 (1954): 417-451.
Mehta, C. R., Nitin P., and Pralay S. Exact stratified linear rank tests for ordered categorical and binary data. Journal of Computational and Graphical Statistics, 1 (1992): 21-40.
Portier, C., and Hoel D. Type 1 error of trend tests in proportions and the design of cancer screens. Communications in Statistics-Theory and Methods, 13 (1984): 1-14.
Williams, D. A. Tests for differences between several small proportions. Applied Statistics, 37 (1988): 421-434.
Examples
d <- c(1,2,3,4)
n <- rep(20,4)
r <- c(1,4,3,8)
catt_exact(d, n, r)