grid-stuff: Tools For Working with Variable Specification Lists
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grid-stuff

R Documentation

Tools For Working with Variable Specification Lists

Description

From a variable specification list (varlist),

getEl(): gets elements of a variable specification list that match the given variable type.
mkGrid(): builds a grid, e.g., for parallel evaluation, basically by calling do.call(expand.grid, <list>).
mkNms(): builds a list of names, e.g., to be used as dimnames for a corresponding simulation result array.
get.n.sim(): extracts n.sim or returns 1 if it is not contained in vList.
set.n.sim(): modifies or sets n.sim in vList.
get.nonGrids(): extracts all variables not having type="grid" and returns n.sim the same as get.n.sim().

Usage

getEl       (vList, type = "ALL", comp = "value")
mkGrid      (vList)
mkNms       (vList, addNms = FALSE)
get.n.sim   (vList)
set.n.sim   (vList, n)
get.nonGrids(vList)

Arguments

`vList`	a `list` of variable specifications, typically resulting from `varlist()`. Each variable spec is itself a named list which must contain a `"value"` component.
`type`	`character` vector of variable type or types to restrict the selection to. The default, `"ALL"` implies no restriction and hence returns all variables.
`comp`	either a `character` string containing the component name to pick out or `NA` (in which case all components are picked out).
`addNms`	logical, specifying if the resulting names should be of the form `<var>=<value>` instead of just `<value>`.
`n`	for `set.n.sim()`: the value `n.sim` should be set to; an integer or `NULL`.

Details

These functions are useful when working with variable specification lists.

Value

For

getEl(): a named list containing the selected components of those variables that match the provided type.
mkGrid(): a data frame (data.frame).
mkNms(): a named list of the same length() and with the same names() as vList.
get.n.sim(): n.sim if it is contained in vList, 1 otherwise.
set.n.sim(): the varlist vList with a modified n.sim.
get.nonGrids(): list of length 2 containing the (possibly modified) n.sim and a list containing all variables not having type="grid".

Author(s)

Marius Hofert and Martin Maechler.

Examples

vList <-
 varlist(n.sim = list(type="N", expr = quote(N[sim]), value = 64),
         n     = list(type="grid",
                      value = c(20, 100, 500)), # sample sizes
         p     = list(type="grid",
                      value = c(3, 7, 15, 25)), # dimensions
         meth  = list(type="grid", expr = quote(italic(method)),
                      value = c("classical", "robust")))

getEl(vList, type="grid") # for those of type "grid", get all values
## for those of type "grid", get all components :
str(getEl(vList, type="grid", comp=NA))
stopifnot(identical(as(vList, "list"),
                    getEl(vList, type=c("N","grid"), comp = NA)))

(grd <- mkGrid(vList))
stopifnot(nrow(grd) == 3*4*2, ncol(grd) == 3)

getEl(vList)# -> all "value"s: the same as lapply(., `[[`, "value") :
stopifnot(identical(lapply(vList, `[[`, "value"),
                    getEl(vList)))
mkNms(vList)
mkNms(vList, addNms=TRUE)

get.n.sim(vl. <- set.n.sim(vList, NULL)) # 1
vl.$n.sim # NULL
set.n.sim(vl., 12)

simsalapar documentation built on Aug. 8, 2025, 7:49 p.m.