upscaleUmatrix

Use linear interpolation to increase the size of a umatrix. This can be used to produce nicer ggplot plots in <code>plotTopographicMap</code> and is going to be used for further normalization of the umatrix.

U-Matrix

Projections are common dimensionality reduction methods, which represent high-dimensional data in a two-dimensional space. However, when restricting the output space to two dimensions, which results in a two dimensional scatter plot (projection) of the data, low dimensional similarities do not represent high dimensional distances coercively [Thrun, 2018] <DOI: 10.1007/978-3-658-20540-9>. This could lead to a misleading interpretation of the underlying structures [Thrun, 2018]. By means of the 3D topographic map the generalized Umatrix is able to depict errors of these two-dimensional scatter plots. The package is derived from the book of Thrun, M.C.: "Projection Based Clustering through Self-Organization and Swarm Intelligence" (2018) <DOI:10.1007/978-3-658-20540-9> and the main algorithm called simplified self-organizing map for dimensionality reduction methods is published in <DOI: 10.1016/j.mex.2020.101093>.

Michael Thrun

GeneralizedUmatrix

Credible Visualization for Two-Dimensional Projections of Data

Felix Pape

Tim Schreier

Luis Winckelman

Quirin Stier

Alfred Ultsch

upscaleUmatrix function

<dl><dt>Umatrix</dt>
<dd>The umatrix which should be upscaled</dd><dt>BestMatches</dt>
<dd>The BestMatches which should be upscaled</dd><dt>Factor</dt>
<dd>Optional: The factor by which the axes will be scaled. Be aware
that the size of the matrix will grow by Factor squared. Default: 2</dd><dt>Imx</dt>
<dd>Optional: Island cutout of the umatrix. Should also be scaled to the
new size of the umatrix.</dd></dl>

Arguments

Author

Upscale a Umatrix grid — upscaleUmatrix

<dl>

<dt>Umatrix</dt>
<dd>The umatrix which should be upscaled</dd>

<dt>BestMatches</dt>
<dd>The BestMatches which should be upscaled</dd>

<dt>Factor</dt>
<dd>Optional: The factor by which the axes will be scaled. Be aware
that the size of the matrix will grow by Factor squared. Default: 2</dd>

<dt>Imx</dt>
<dd>Optional: Island cutout of the umatrix. Should also be scaled to the
new size of the umatrix.</dd>

</dl>

upscaleUmatrix: Upscale a Umatrix grid

Description

Usage

Value

Arguments

Author