Attach: Attach the simulation conditions for easier reference

Description

This function accepts the condition object used to indicate the design conditions and makes the variable names available in the environment from which it is called. 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(condition, check = TRUE, attach_listone = TRUE)

Arguments

condition

a data.frame or tibble containing the condition names

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]]

Details

The behavior 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.

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. 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. 10.1080/10691898.2016.1246953

Examples

Run this code

# 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
}

# }