Tidy a(n) optim object masquerading as list

Broom tidies a number of lists that are effectively S3 objects without a class attribute. For example, stats::optim(), svd() and akima::interp() produce consistent output, but because they do not have a class attribute, they cannot be handled by S3 dispatch.

These functions look at the elements of a list and determine if there is an appropriate tidying method to apply to the list. Those tidiers are themselves are implemented as functions of the form tidy_<function> or glance_<function> and are not exported (but they are documented!).

If no appropriate tidying method is found, throws an error.

tidy_optim(x, ...)

Arguments

x

A list returned from stats::optim().

...

Additional arguments. Not used. Needed to match generic signature only. Cautionary note: Misspelled arguments will be absorbed in ..., where they will be ignored. If the misspelled argument has a default value, the default value will be used. For example, if you pass conf.lvel = 0.9, all computation will proceed using conf.level = 0.95. Additionally, if you pass newdata = my_tibble to an augment() method that does not accept a newdata argument, it will use the default value for the data argument.

Value

A tibble::tibble with one row per parameter estimated by optim and columns:

parameter

name of the parameter, or parameter1, parameter2... if the input vector is not named

value

parameter value that minimizes or maximizes the output

See also

tidy(), stats::optim()

Other list tidiers: glance_optim, list_tidiers, tidy_irlba, tidy_svd, tidy_xyz

Examples

func <- function(x) {
    (x[1] - 2)^2 + (x[2] - 3)^2 + (x[3] - 8)^2
}

o <- optim(c(1, 1, 1), func)

tidy(o)
#> # A tibble: 3 x 2
#>   parameter  value
#>   <chr>      <dbl>
#> 1 parameter1  2.00
#> 2 parameter2  3.00
#> 3 parameter3  8.00
glance(o)
#> # A tibble: 1 x 4
#>         value function.count gradient.count convergence
#>         <dbl>          <int>          <int>       <int>
#> 1 0.000000368            144             NA           0