The function GRF()
generates random frequencies based on a design, i.e.,
a list giving the factors and the categories with each factor.
The data are given in the compiled format.
GRF( design, n, prob = NULL, f = "Freq" )A list with the factors and the categories within each.
How many simulated participants are to be classified.
(optional) the probability of falling in each cell of the design.
(optional) the column names that will contain the frequencies.
a data frame containing frequencies per cells of the design.
The name of the function GRF() is derived from grd(),
a general-purpose tool to generate random data (Calderini and Harding 2019)
now bundled
in the superb package (Cousineau et al. 2021)
.
Calderini M, Harding B (2019).
“GRD for R: An intuitive tool for generating random data in R.”
The Quantitative Methods for Psychology, 15(1), 1--11.
doi:10.20982/tqmp.15.1.p001
.
Cousineau D, Goulet M, Harding B (2021).
“Summary plots with adjusted error bars: The superb framework with an implementation in R.”
Advances in Methods and Practices in Psychological Science, 4, 1--18.
doi:10.1177/25152459211035109
.
# The first example disperse 20 particants in one factor having
# two categories (low and high):
design <- list( A=c("low","high"))
GRF( design, 20 )
#> A Freq
#> 1 low 7
#> 2 high 13
# This example has two factors, with factor A having levels a, b, c:
design <- list( A=letters[1:3], B = c("low","high"))
GRF( design, 40 )
#> A B Freq
#> 1 a low 9
#> 2 b low 7
#> 3 c low 4
#> 4 a high 2
#> 5 b high 9
#> 6 c high 9
# This last one has three factors, for a total of 3 x 2 x 2 = 12 cells
design <- list( A=letters[1:3], B = c("low","high"), C = c("cat","dog"))
GRF( design, 100 )
#> A B C Freq
#> 1 a low cat 8
#> 2 b low cat 7
#> 3 c low cat 10
#> 4 a high cat 10
#> 5 b high cat 11
#> 6 c high cat 5
#> 7 a low dog 4
#> 8 b low dog 8
#> 9 c low dog 9
#> 10 a high dog 7
#> 11 b high dog 10
#> 12 c high dog 11
# To specify unequal probabilities, use
design <- list( A=letters[1:3], B = c("low","high"))
GRF( design, 100, c(.05, .05, .35, .35, .10, .10 ) )
#> A B Freq
#> 1 a low 2
#> 2 b low 4
#> 3 c low 32
#> 4 a high 37
#> 5 b high 8
#> 6 c high 17
# The name of the column containing the frequencies can be changes
GRF( design, 100, f="patate")
#> A B patate
#> 1 a low 17
#> 2 b low 18
#> 3 c low 18
#> 4 a high 10
#> 5 b high 16
#> 6 c high 21