Restrict a Support to an Interval

Cut a support down to the part of it lying within [from, to].

Usage

support_restrict(
  support,
  ...,
  from = -Inf,
  to = Inf,
  include_from = TRUE,
  include_to = TRUE
)

Arguments

support

A support object, or a distribution.

...

Not used; must be empty. Present so that the arguments below are matched by name.

from, to

Endpoints of the interval to restrict to.

include_from, include_to

Whether the endpoints themselves are kept.

Value

A support object.

Details

The include_* flags apply to the atoms only. An endpoint of a continuous interval carries no probability either way, so including or excluding it makes no difference to the continuous part.

Restricting to a region the support does not reach gives empty_support(), which is the reason that object exists.

See also

support_union() to combine supports instead.

Other Support algebra: support_add_atoms(), support_contains(), support_transform(), support_union()

Examples

support_restrict(continuous(c(0, 10)), from = 3, to = 6)
#> <support: continuous>
#> -- continuous --
#> [3, 6]
support_restrict(discrete(natural0()), to = 4)
#> <support: discrete>
#> -- atoms --
#> Subset series of length 5:
#> 0, 1, 2, 3, 4

# Excluding an endpoint drops the atom sitting on it.
support_restrict(discrete(natural0()), to = 4, include_to = FALSE)
#> <support: discrete>
#> -- atoms --
#> Subset series of length 4:
#> 0, 1, 2, 3

# Restricting out of reach gives the empty support.
support_restrict(continuous(c(0, 1)), from = 5, to = 6)
#> <support: empty>