The following node is available in the Open Source KNIME predictive analytics and data mining platform version 2.7.1. Discover over 1000 other nodes, as well as enterprise functionality at http://knime.com.

MDS Projection (DistMatrix)

This node maps data of a high dimensional space onto a lower (usually 2 or 3) dimensional space with respect to a set of fixed data points. Therefore modified Sammons mapping is applied, which iteratively decreases the difference of the distances of high and low dimensional data. When adjusting the position of a low dimensional data point by default not its neighbors (or all other data points) are taken into account but a specified set of fixed data points which are not modified. Additionally all the other data points (and not only the fixed points) can be taken into account when adjusting its positions, therefore the setting "Project only" has to be unchecked. If the setting is checked the data points will be mapped only with respect to the fixed data. The distances of the data points to project in high dimensional space as well as the distances of the fixed data (to the data to project) must be provided by distance matrix columns.

Dialog Options

Number of rows to use
Specifies the number of rows to apply the MDS on.
Project only
If checked the input data is mapped only with respect to the specified fixed data points (see tab 'Fixed data'). If unchecked, the other (not fixed) data points are taken into account too, when adjusting the position of each single data point.
Epochs
Specifies the number of epochs to train.
Learn rate
Specifies the learning rate to use. The learning rate is decreased automatically over the trained epochs.
Random seed
Specifies the random seed to use, which allows to reproduce a mapping even if the initialization is done randomly.
Output dimension
Specifies the dimension of the mapped output data.
Distance matrix column of data to project
The column (of data table at port 1) containing the distances of the data points to project (to itself and the data points to project).
MDS columns
Specifies the columns to use as fixed (mds column) data. Be aware that the chosen columns represent the lower dimensional data which is used to project the input data to. The number of columns to choose has to be equal to the output dimension.
Distance matrix column of fixed data
The column (of data table at port 0) containing the distances of the fixed data points (to itself and the data points to project).

Ports

Input Ports
0 Data table containing the fixed data points.
1 Data table containing the data to map.
Output Ports
0 The input data and the mapped data.
This node is contained in KNIME Distance Matrix Extension provided by KNIME GmbH, Konstanz, Germany.