| creategroups {biotools} | R Documentation |
Creating Homogeneous Groups
Description
A function to create homogeneous groups of named objects according to an objective function evaluated at a covariate. It can be useful to design experiments which contain a fixed covariate factor.
Usage
creategroups(x, ngroups, sizes, fun = mean, tol = 0.01, maxit = 200)
Arguments
x |
a numeric vector of a covariate at which to evaluate the objective function. |
ngroups |
the number of groups to create. |
sizes |
a numeric vector of length equal to |
fun |
the objective function, i.e., to create groups with similar |
tol |
the tolerance level to define the groups as homogenenous; see details. |
maxit |
the maximum number of iterations; default is 200. |
Details
creategroups uses a tol value to evaluate the following statistic:
h = \sum_{j}^{ngroups} abs( t_{j+1} - t_j ) / ngroups, where t_j = fun(group_j).
If h \leq tol, the groups are considered homogeneous.
Value
A list of
covar |
a character indicating the name of the covariate. |
func |
a character indicating the name of the objective function. |
val.func |
a numeric vector containing the values evaluated by |
niter |
the number of iteration require to achieve convergence. |
labels |
a list containing the labels of the objects in each group. |
groups |
a list of named vectors containing the values for the groups |
Author(s)
Anderson Rodrigo da Silva <anderson.agro@hotmail.com>
Examples
x <- rnorm(10, 1, 0.5)
names(x) <- letters[1:10]
creategroups(x, ngroups = 2, sizes = c(5, 5))
creategroups(x, ngroups = 3, sizes = c(3, 4, 3), tol = 0.05)
# End (not run)