inclusion_prob()
is now faster with a single
stratum, improving the performance of sps()
and
expected_coverage()
.
By default, sps_repweights()
automatically picks the
smallest tau
to keep the replicate weights from being
negative. Inspired by
svrep::make_gen_boot_factors()
.
Now requires R >= 4.1, which has been the case for a while (closing #2).
Added becomes_ta()
to determine the sample size when
a unit enter the take-all stratum.
Internal changes to the way classes are instantiated. No user-visible changes.
Updated maintainer email.
Added a vignette.
A single sample size is now recycled for each stratum when drawing samples or calculating inclusion probabilities.
Added a cutoff
argument that puts units with sizes
above the cutoff into a take-all stratum.
sps
objects now inherit from numeric instead of
integer.
Replacement methods for length
and
levels
no longer mangle sps
objects.
prop_allocation()
gets a new argument for breaking
ties. The default now breaks ties according to the references; the old
behavior can be had by setting ties = "first"
.
Argument names for prop_allocation()
,
expected_coverage()
, and sps_repweights()
have
changed to be either more descriptive, or consistent with the names for
other functions.
Fixed a bug when calculating inclusion probabilities that could
result in ties not breaking according to position (as documented) when
alpha > 0
.
Simplified the codebase.
Added a new argument alpha
for calculating inclusion
probabilities. It can be used to place units with inclusion
probabilities close to 1 into the take-all stratum. This was implicitly
0 in previous versions, but the current default is 1e-4.
All functions can now accept size vectors with zeros.
sps()
is now faster, especially for large
populations.
Added a function factory to generate other order sampling methods.
This version has a number of non-backwards compatible changes to address undesirable behavior with some functions.
Largest-remainder rounding could result in
prop_allocation()
giving visibly non-proportional
allocations, so it has been removed. The default is now the
Jefferson/D’Hondt method.
The method
argument in
prop_allocation()
has been replaced with the
divisor
argument to supply a divisor function for
rounding.
The initial
argument in
prop_allocation()
is recycled to ensure the initial
allocation is feasible when supplying a single value. This change is not
strictly backwards compatible as values that could not be ordinarily
recycled no longer give an error.
Supplying a vector of permanent random numbers to
sps()
or ps()
that are generated with a given
seed now gives the same result when setting that seed prior to calling
sps()
or ps()
. This means that setting the
seed to a given value can give a different sample compared to older
versions, although permanent random numbers should be used for
reproducible samples.
The argument name for specifying strata is now
strata
instead of s
in all functions. Partial
matching means this change won’t break existing code.
prop_allocation()
gains two new arguments:
initial
sets the initial allocation for each
stratum. This saves from having to manually keep track of an initial
allocation and adjust the sample size passed to
prop_allocation()
.
method
selects the apportionment method used to
round a proportional allocation to integer values. In particular,
highest-averages methods can be used in place of the largest-remainder
method.
The defaults for these arguments do not change the behavior of the function from previous versions.
A few convenience functions have been added:
ps()
for drawing ordinary Poisson samples with the
same interface as sps()
.
inclusion_prob()
for generating inclusion
probabilities for a frame.
expected_coverage()
for calculating the expected
number of strata when sampling from a frame.
Some of the internals have been updated to improve performance with large frames.
Most functions do a little more argument checking. In particular,
it is no longer possible to pass length 0 arguments to
sps()
, prop_allocation()
, or
sps_repweights()
.
Added the option to draw samples with permanent random numbers.
Added methods for Math, Ops, [<-, and [[<- that strip
attributes from sps
objects so as not to treat the result
as a sample.
sps()
now returns an integer vector (when possible),
rather than a double.
printing the matrix of replicate weights now shows row names (if any).