Attach: Attach objects for easier reference

In SimDesign: Structure for Organizing Monte Carlo Simulation Designs

Attach objects for easier reference

Description

The behaviour of this function is very similar to attach, however it is environment specific, and therefore only remains defined in a given function rather than in the Global Environment. Hence, this function is much safer to use than the attach, which incidentally should never be used in your code. This is useful primarily as a convenience function when you prefer to call the variable names in condition directly rather than indexing with condition$sample_size or with(condition, sample_size), for example.

Usage

Attach(..., omit = NULL, check = TRUE, attach_listone = TRUE)

Arguments

...	a comma separated list of data.frame or tibble objects containing elements that should be placed in the current working environment
omit	an optional character vector containing the names of objects that should not be attached to the current environment. For instance, if the objects named 'a' and 'b' should not be attached then use omit = c('a', 'b'). When NULL (default) all objects are attached
check	logical; check to see if the function will accidentally replace previously defined variables with the same names as in condition? Default is TRUE, which will avoid this error
attach_listone	logical; if the element to be assign is a list of length one then assign the first element of this list with the associated name. This generally avoids adding an often unnecessary list 1 index, such as name <- list[[1L]]

Author(s)

Phil Chalmers [e-mail]

References

Chalmers, R. P., & Adkins, M. C. (2020). Writing Effective and Reliable Monte Carlo Simulations with the SimDesign Package. The Quantitative Methods for Psychology, 16(4), 248-280. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.20982/tqmp.16.4.p248")}

Sigal, M. J., & Chalmers, R. P. (2016). Play it again: Teaching statistics with Monte Carlo simulation. Journal of Statistics Education, 24(3), 136-156. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1080/10691898.2016.1246953")}

See Also

runSimulation, Generate

Examples

## Not run: 

# does not use Attach()
Generate <- function(condition, fixed_objects = NULL) {
    N1 <- condition$sample_sizes_group1
    N2 <- condition$sample_sizes_group2
    sd <- condition$standard_deviations

    group1 <- rnorm(N1)
    group2 <- rnorm(N2, sd=sd)
    dat <- data.frame(group = c(rep('g1', N1), rep('g2', N2)),
                      DV = c(group1, group2))
    dat
}

# similar to above, but using the Attach() function instead of indexing
Generate <- function(condition, fixed_objects = NULL) {
    Attach(condition)
    N1 <- sample_sizes_group1
    N2 <- sample_sizes_group2
    sd <- standard_deviations

    group1 <- rnorm(N1)
    group2 <- rnorm(N2, sd=sd)
    dat <- data.frame(group = c(rep('g1', N1), rep('g2', N2)),
                      DV = c(group1, group2))
    dat
}


## End(Not run)

SimDesign documentation built on Oct. 17, 2023, 5:07 p.m.