It will assist the user to find simple quadratic roots from any quadratic equation.

Fits classical sparse regression models with
    efficient active set algorithms by solving quadratic problems as described by 
    Grandvalet, Chiquet and Ambroise (2017) <doi:10.48550/arXiv.1210.2077>. Also provides a few
    methods for model selection purpose (cross-validation, stability selection).

Provides functionality for working with raster-like quadtrees
    (also called “region quadtrees”), which allow for variable-sized
    cells. The package allows for flexibility in the quadtree creation
    process.  Several functions defining how to split and aggregate cells
    are provided, and custom functions can be written for both of these
    processes. In addition, quadtrees can be created using other quadtrees
    as “templates”, so that the new quadtree's structure is identical to
    the template quadtree. The package also includes functionality for
    modifying quadtrees, querying values, saving quadtrees to a file, and
    calculating least-cost paths using the quadtree as a resistance
    surface.

An easy framework to set a quality control workflow on a dataset.
  Includes a various range of functions that allow to establish an adaptable 
  data quality control.

Provides a set of functions for taking qualitative GIS data, hand drawn on a map, and 
   converting it to a simple features object. These tools are focused on data that are drawn on a map
   that contains some type of polygon features. For each area identified on the map, the id numbers
   of these polygons can be entered as vectors and transformed using qualmap.

Automatic generation of maximally distinct qualitative color palettes,
    optionally tailored to color deficiency. A list of colors or a subspace
    of a color space is used as input and then projected to the DIN99d color space,
    where colors that are maximally distinct are chosen algorithmically.

Provides functions to access survey results directly into R
    using the 'Qualtrics' API. 'Qualtrics'
    <https://www.qualtrics.com/about/> is an online survey and data
    collection software platform. See <https://api.qualtrics.com/> for
    more information about the 'Qualtrics' API.  This package is
    community-maintained and is not officially supported by 'Qualtrics'.