Access data and processing functionalities of 'openEO' compliant back-ends in R.

Provides programmatic access to the Open Experience Sampling Method ('openESM') database (<https://openesmdata.org>), 
    a collection of harmonized experience sampling datasets. The package enables researchers to discover, download, 
    and work with the datasets while ensuring proper citation and license compliance.

The 'openFDA' API facilitates access to Federal Drug Agency (FDA)
  data on drugs, devices, foodstuffs, tobacco, and more with 'httr2'. This
  package makes the API easily accessible, returning objects which the user can
  convert to JSON data and parse. Kass-Hout TA, Xu Z, Mohebbi M et al. (2016)
  <doi:10.1093/jamia/ocv153>.

Social media sites often embed cards when links are shared, based on
    metadata in the 'Open Graph Protocol' (<https://ogp.me/>). This supports extracting
    that metadata from a website. It further allows for the creation of tags to
    add to a website to support the 'Open Graph Protocol' and provides a list of the
    standard tags and their required properties.

The comprehensive knowledge of epigenetic modifications in plants, encompassing histone modifications in regulating gene expression, is not completely ingrained. It is noteworthy that histone deacetylation and histone H3 lysine 27 trimethylation (H3K27me3) play a role in repressing transcription in eukaryotes. In contrast, histone acetylation (H3K9ac) and H3K4me3 have been inevitably linked to the stimulation of gene expression, which significantly influences plant development and plays a role in plant responses to biotic and abiotic stresses. To our knowledge this the first multiclass classifier for predicting histone modification in plants. <doi:10.1186/s12864-019-5489-4>.

Provides dates for public and school holidays for a number of
    countries and their subdivisions through the 'OpenHolidays' API at
    <https://www.openholidaysapi.org/en/>.

Incorporates functions for image preprocessing, filtering and image recognition. The package takes advantage of 'RcppArmadillo' to speed up computationally intensive functions. The histogram of oriented gradients descriptor is a modification of the 'findHOGFeatures' function of the 'SimpleCV' computer vision platform, the average_hash(), dhash() and phash() functions are based on the 'ImageHash' python library. The Gabor Feature Extraction functions are based on 'Matlab' code of the paper, "CloudID: Trustworthy cloud-based and cross-enterprise biometric identification" by M. Haghighat, S. Zonouz, M. Abdel-Mottaleb, Expert Systems with Applications, vol. 42, no. 21, pp. 7905-7916, 2015, <doi:10.1016/j.eswa.2015.06.025>. The 'SLIC' and 'SLICO' superpixel algorithms were explained in detail in (i) "SLIC Superpixels Compared to State-of-the-art Superpixel Methods", Radhakrishna Achanta, Appu Shaji, Kevin Smith, Aurelien Lucchi, Pascal Fua, and Sabine Suesstrunk, IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 34, num. 11, p. 2274-2282, May 2012, <doi:10.1109/TPAMI.2012.120> and (ii) "SLIC Superpixels", Radhakrishna Achanta, Appu Shaji, Kevin Smith, Aurelien Lucchi, Pascal Fua, and Sabine Suesstrunk, EPFL Technical Report no. 149300, June 2010.