Some meta updates (biblio and maintenance change) and minor fixes, detailed below.
stats
with ::
.port()
fully moved
to C, with improved headers, error codes and memory management. Style now
following c99.This update of gmat
incorporates functions necessary to run the experiments in
Córdoba et al. (2019), and some minor
improvements and bug fixes.
chol_polar()
has been removed because a faster implementation has
been recently provided by the
randcorr package.anti_t()
has been replaced by a more useful function uchol()
,
which by transposing with respect to the antidiagonal obtains the upper
Cholesky factor of a positive definite diagonal matrix (see Córdoba et al.
2019, and the documentation of the function).port_chol()
which implements a combination of the algorithms in
chol_mh()
and port()
, see Córdoba et al. (2019) for the details.ug_to_dag()
for obtaining an acyclic digraph with no
v-structures from the chordal cover of an undirected graph.port()
and diagdom()
.port()
, now it is faster.rgraph()
allows now to generate acyclic digraphs with any
topological sorting of their nodes, by setting to FALSE
its new ordered
argument. Examples have also been added to the documentation of this function.mh_u()
works for any topological sort of a dag, not just the
standard 1, ..., p
.In this version the functionality of gmat
has been significantly extended.
In addition to the functionality already available for sampling covariance
matrices, possibly with a zero pattern specified by an undirected graph, now the
package also allows sampling correlation matrices with zero entries on their
Cholesky factor, represented by an acyclic digraph.
Arguments for port()
and diagdom()
have been refactored in order to unify the
approaches for undirected graphs and the new functions for acyclic digraphs.
This has had some consequences in terms of the behaviour of the two functions.
ug
is now the fourth argument, instead of the
second one, for both functions.ug
is
not provided, unless explicitly stating a parameter d < 1
.p
and d
have been changed. Now by default
one 3 x 3
full matrix is returned.rentries
has been removed for both functions. In the future maybe this
argument is reintroduced with a more complete checking of its validity
depending on the properties of the function.k
has been removed from diagdom()
, and its functionality is now
implemented by the utility function set_cond_number()
.The main addition in this version are functions for correlation matrix sampling, possibly with constraints on the upper Cholesky factorization, which correspond to an acyclic digraph representation. Some side utility functions are also provided.
chol_mh()
, chol_iid()
and chol_polar()
. These three
functions return a sample of correlation matrices, possibly with an average
percentage of zeros in their upper Cholesky factor, which can be also
predefined by a given acyclic digraph. See more details at their
documentation.mh_sphere()
and mh_u()
, used by chol_mh()
,
allows to sample the upper Cholesky factor of a correlation
matrix by sampling vectors on hemispheres of different
dimensions. More information on their documentation.rgraph()
, which is a simple wrapper of some
functionality in package igraph
for random graph generation.anti_t()
computes the anti transpose of a matrix. This is
mainly useful for testing, since it is involved in the acyclic digraph
representation of the upper and lower Cholesky factors.vectorize()
for extracting the upper/lower triangle in a
covariance/correlation matrix sample as returned by the functions in the
package.port()
and diagdom()
.NAMESPACE
, but instead explicitly called throughout the
package using ::
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