paradox
Package website: release | dev
Universal Parameter Space Description and Tools.
Installation
remotes::install_github("mlr-org/paradox")Usage
Create a simple ParamSet using all supported Parameter Types:
- integer numbers (
"int") - real-valued numbers (
"dbl") - truth values
TRUEorFALSE("lgl") - categorical values from a set of possible strings (
"fct") - further types are only possible by using transformations.
ps = ParamSet$new(
params = list(
ParamInt$new(id = "z", lower = 1, upper = 3),
ParamDbl$new(id = "x", lower = -10, upper = 10),
ParamLgl$new(id = "flag"),
ParamFct$new(id = "methods", levels = c("a","b","c"))
)
)Draw random samples / create random design:
generate_design_random(ps, 3)
#> <Design> with 3 rows:
#> z x flag methods
#> 1: 1 7.660348 FALSE b
#> 2: 3 8.809346 FALSE c
#> 3: 2 -9.088870 FALSE bGenerate LHS Design:
requireNamespace("lhs")
#> Loading required namespace: lhs
generate_design_lhs(ps, 3)
#> <Design> with 3 rows:
#> z x flag methods
#> 1: 1 -3.984673 TRUE b
#> 2: 2 7.938035 FALSE a
#> 3: 3 1.969783 TRUE cGenerate Grid Design:
generate_design_grid(ps, resolution = 2)
#> <Design> with 24 rows:
#> z x flag methods
#> 1: 1 -10 TRUE a
#> 2: 1 -10 TRUE b
#> 3: 1 -10 TRUE c
#> 4: 1 -10 FALSE a
#> 5: 1 -10 FALSE b
#> 6: 1 -10 FALSE c
#> 7: 1 10 TRUE a
#> [ reached getOption("max.print") -- omitted 18 rows ]Properties of the parameters within the ParamSet:
ps$ids()
#> [1] "z" "x" "flag" "methods"
ps$levels
#> $z
#> NULL
#>
#> $x
#> NULL
#>
#> $flag
#> [1] TRUE FALSE
#>
#> $methods
#> [1] "a" "b" "c"
ps$nlevels
#> z x flag methods
#> 3 Inf 2 3
ps$is_number
#> z x flag methods
#> TRUE TRUE FALSE FALSE
ps$lower
#> z x flag methods
#> 1 -10 NA NA
ps$upper
#> z x flag methods
#> 3 10 NA NAParameter Checks
Check that a parameter satisfies all conditions of a ParamSet, using
$test() (returns FALSE on mismatch), $check() (returns error
description on mismatch), and $assert() (throws error on mismatch):
ps$test(list(z = 1, x = 1))
#> [1] TRUE
ps$test(list(z = -1, x = 1))
#> [1] FALSE
ps$check(list(z = -1, x = 1))
#> [1] "z: Element 1 is not >= 1"
ps$assert(list(z = -1, x = 1))
#> Error in ps$assert(list(z = -1, x = 1)): Assertion on 'list(z = -1, x = 1)' failed: z: Element 1 is not >= 1.Transformations
Transformations are functions with a fixed signature.
xA named list of parameter valuesparam_settheParamSetused to create the design
Transformations can be used to change the distributions of sampled parameters. For example, to sample values between (2^-3) and (2^3) in a (log_2)-uniform distribution, one can sample uniformly between -3 and 3 and exponentiate the random value inside the transformation.
ps = ParamSet$new(
params = list(
ParamInt$new(id = "z", lower = -3, upper = 3),
ParamDbl$new(id = "x", lower = 0, upper = 1)
)
)
ps$trafo = function(x, param_set) {
x$z = 2^x$z
return(x)
}
ps_smplr = SamplerUnif$new(ps)
x = ps_smplr$sample(2)
xst = x$transpose()
xst
#> [[1]]
#> [[1]]$z
#> [1] 0.125
#>
#> [[1]]$x
#> [1] 0.4137243
#>
#>
#> [[2]]
#> [[2]]$z
#> [1] 0.5
#>
#> [[2]]$x
#> [1] 0.3688455Further documentation can be found in the mlr3book.