seq_pbib_clatworthy_williams: Clatworthy-Williams cross-over design specification
In mjg211/xover: Design and analysis of cross-over clinical trials

Description Usage Arguments Details Value Author(s) References See Also Examples

View source: R/seq_clatworthy_williams.R

Specifies cross-over designs based on combining Clatworthy (1973) designs with Williams (1949) designs.

1 2	seq_pbib_clatworthy_williams(williams_D = 3, type = "R", selection = 42, labels, as_matrix = T, summary = T)

`type`	A `character` string indicating which type of sequences to return. Must be one of `"R"`, `"S"`, and `"SR"`. Defaults to `"R"`.
`selection`	A `numeric` integer or `character` string indicating which design to return, for the chosen values of `williams_D` and `type`. See Details for information on how to ascertain supported values. Defaults to `1`.
`labels`	A `vector` of labels for the treatments. If specified, should have `length` corresponding to the number of treatments in the chosen design, containing unique elements. If missing, will internally default to `0:(D - 1)`, where `D` is the number of treatments.
`as_matrix`	A `logical` variable indicating whether the design should be returned as a `matrix`, or a `tibble`. Defaults to `T`.
`summary`	A `logical` variable indicating whether a summary of the function's progress should be printed to the console. Defaults to `T`.
`D`	The number of treatments in the utilised Williams (1949) design. Must be a single `numeric` integer between three and nine inclusive. Defaults to `3`.

seq_clatworthy_williams() supports the specification of designs based on combining designs from Clatworthy (1973) with designs from Williams (1949). Designs for a large array of values of the number of treatments and periods are available (accessible by setting williams_D, selection and type carefully), for any chosen treatment labels (see labels). In addition, the designs can be returned in matrix or tibble form (see as_matrix).

Precisely, type must be set as one of "R", "S", and "SR". Then, williams_D must be set to an integer between three and nine inclusive. With this, selection can take one of a particular set of numeric or character values. The best way to ascertain which values are allowed is to use the utility function summary_seq_clatworthy_williams. Ultimately, the (k,j)th element of the cross-over design matrix corresponds to the treatment a subject on the kth sequence would receive in the jth period.

Either a matrix if as_matrix = T (with rows corresponding to sequences and columns to periods), or a tibble if as_matrix = F (with rows corresponding to a particular period on a particular sequence). In either case, the returned object will have class xover_seq.

Based on data from the Crossover package by Kornelius Rohmeyer.

Clatworthy WH, Cameron JM, Speckman JA (1973) Tables of two-associate-class partially balanced designs. US Government Printing Office.

Patterson HD, Lucas HL (1962) Change-over designs. North Carolina Agricultural Experiment Station. Tech Bull 147.

Williams EJ (1949) Experimental designs balanced for the estimation of residual effects of treatments. Aust J Sci Res Ser A 2:149-168.

summary_seq_clatworthy_williams.

# A six treatment design
clatworthy_williams        <- seq_clatworthy_williams()
# Using different labels
clatworthy_williams_ABCDEF <- seq_clatworthy(labels = LETTERS[1:6])
# Returning in tibble form
clatworthy_williams_tibble <- seq_clatworthy(as_matrix = F)