| add.jitter {UCS} | R Documentation |
Add random jitter to the frequency signatures in a data set, in
order to avoid ties in rankings according to GAM scores and to facilitate
visualisation of the data set with eo and ebo plots. The
add.ebo function is used to re-compute ebo-coordinates from
the jittered frequency signatures.
add.jitter(ds, amount=0.5, overwrite=FALSE) has.jitter(ds, fail=FALSE) add.ebo(ds, jitter=FALSE)
ds |
a UCS data set object |
amount |
amount of jitter to be added; the jitter vector for each
coordinate (f, f1, f2) has a uniform distribution over the
range [-amount, +amount] |
overwrite |
if TRUE, overwrite existing jitter vectors in
the data set |
fail |
if TRUE, abort with an error message unless the
data set contains jitter vectors |
jitter |
if TRUE, use the jittered frequency signatures to
compute ebo-coordinates (default: unjittered integer frequencies) |
The add.jitter function adds jitter vectors for the joint and
marginal frequencies (f, f1, f2) to a data set, i.e. uniformly
distributed random numbers in the range [-amount, +amount].
These vectors are stored in variables x.jitter.f,
x.jitter.f1 and x.jitter.f2, where they can be used by
add.ebo, add.gams and other functions.
has.jitter tests for the presence of these variables.
add.ebo computes ebo-coordinates from the frequency signatures
and stores them in the standard variables e, b, o. Unlike the
values computed with UCS/Perl tools, add.ebo uses jitter
vectors in this computation when the option jitter=TRUE is passed.
add.jitter and add.ebo return a copy of the data set
ds with the request variables added. has.jitter returns
TRUE if the jitter variables are present in ds, and
FALSE otherwise.
ds <- add.jitter(ds, amount=0.2) ds <- add.ebo(ds, jitter=TRUE) # recompute ebo coordinates with jitter