Provides functions to do 'O2PLS-DA' analysis for multiple omics data integration.
            The algorithm came from "O2-PLS, a two-block (X±Y) latent variable regression (LVR) method with an integral OSC filter" 
            which published by Johan Trygg and Svante Wold at 2003 <doi:10.1002/cem.775>. 
            'O2PLS' is a bidirectional multivariate regression method that aims to separate the covariance between
            two data sets (it was recently extended to multiple data sets) (Löfstedt and Trygg, 2011 <doi:10.1002/cem.1388>; Löfstedt et al., 2012 <doi:10.1016/j.aca.2013.06.026>) 
            from the systematic sources of variance being specific for each data set separately.

Provides carefully chosen color palettes as used a.o. at OpenAnalytics <http://www.openanalytics.eu>.

A general purpose client to work with any 'OAI-PMH'
    (Open Archives Initiative Protocol for 'Metadata' Harvesting) service.
    The 'OAI-PMH' protocol is described at
    <http://www.openarchives.org/OAI/openarchivesprotocol.html>.
    Functions are provided to work with the 'OAI-PMH' verbs: 'GetRecord',
    'Identify', 'ListIdentifiers', 'ListMetadataFormats', 'ListRecords', and
    'ListSets'.

Harvest metadata using the Open Archives Initiative Protocol for Metadata
  Harvesting (OAI-PMH) version 2.0 (for more information, see
  <https://www.openarchives.org/OAI/openarchivesprotocol.html>).

A comprehensive set of helpers that streamline data transmission
  and processing, making it effortless to interact with the 'OpenAI' API.

Offers a suite of functions for enhancing R plots.

Implements the efficient algorithm by Ortmann and Brandes (2017)
  <doi:10.1007/s41109-017-0027-2> to compute the orbit-aware frequency distribution of induced and non-induced quads, i.e. subgraphs of size four. Given an edge matrix, data frame, or a graph object (e.g., 'igraph'), the orbit-aware counts are computed respective each of the edges and nodes.

Generalise the starting point of the array index.

An implementation of the Blinder-Oaxaca decomposition for linear regression models.