Produces an object that can be used for adding Targets to an SPC chart. This method provides two different ways to add a target:
You can either provide a single value, which will apply the same target to every facet of an SPC
You can provide named values of targets, where the names correspond to the names of the facets, in order to have different targets for each facet.
Value
Either:
a single numeric value, in this case all facets in the plot will use this target value
a named list of single numeric values, where each item is named as for one of the facets in the plot. If a facet isn't specified then it will not have a target.
Details
This function is a helper to provide data in the correct format for
use with ptd_spc(). See Value section for details of return type. If
you are trying to do something like ptd_spc(list_of_values) then you can
skip using the function and just use list_of_values, so long as the list
meets the requirements as listed above.
Examples
# If you aren't using a faceted chart, or you want to use the same target for
# each facet, you can simply call this method with a single value. For
# example, to use a target of 90%:
ptd_target(0.9)
#> [1] 0.9
# If you are using a faceted chart, and wish to use a different target for
# each facet, then you can call this method, naming each value with the name
# of the facet. Any facet that isn't listed will not have a target applied to
# it.
# For example, to apply a target of 25 to the "a" facet and 10 to the "b"
# facet:
ptd_target(
"a" = 25,
"b" = 10
)
#> $a
#> [1] 25
#>
#> $b
#> [1] 10
#>
# If you already have your data in a list, you do not need to use
# ptd_target(). But, if you wanted to check that your values are valid, you
# could call it like so:
my_targets <- list("a" = 25, "b" = 10)
do.call(ptd_target, my_targets)
#> $a
#> [1] 25
#>
#> $b
#> [1] 10
#>
# or, if your targets are in a numeric vector:
my_targets <- c("a" = 25, "b" = 10)
do.call(ptd_target, as.list(my_targets))
#> $a
#> [1] 25
#>
#> $b
#> [1] 10
#>