is.positive.definite

<p>This function tests whether all eigenvalues of a symmetric matrix are positive. See <code>help("is.positive.definite")</code> from package <code>corpcor</code>.</p>

covariance

positive definite

Functions to fit quantile regression models for hierarchical
data (2-level nested designs) as described in Geraci and
Bottai (2014, Statistics and Computing) <doi:10.1007/s11222-013-9381-9>.
A vignette is given in Geraci (2014, Journal of Statistical Software)
<doi:10.18637/jss.v057.i13> and included in the package documents.
The packages also provides functions to fit quantile models for
independent	data and for count responses.

Marco Geraci

is.positive.definite: Test for Positive Definiteness

Description

Arguments