cornerSort: Candidate combinations as corners
In CAMTHC: Convex Analysis of Mixtures for Tissue Heterogeneity Characterization

Description Usage Arguments Details Value Examples

Given a set of data points, return possible combinations of data points as corners. These combinations are selected by ranking the sum of margin-of-errors.

1	cornerSort(X, K, nComb)

`X`	Data in a matrix. Each column is a data point.
`K`	The number of corner points.
`nComb`	The number of returned combinations of data points as corners. All combinations will be returned if the number of all combinations is less than nComb.

This function is to detect K corner points from M data points by conducting an exhaustive combinatorial search (with total C_M^K combinations), based on a convex-hull-to-data fitting criterion: sum of margin-of-errors. nComb combinations are returned for further selection based on reconstruction errors of all data points in original space.

The function is implemented in Java with R-to-Java interface provided by rJava package. It relies on NonNegativeLeastSquares class in Parallel Java Library (https://www.cs.rit.edu/~ark/pj.shtml).

A list containing the following components:

`idx`	A matrix to show the indexes of data points in combinations to construct a convex hull. Each column is one combination.
`error`	A vector of margin-of-error sums for each combination.

data <- matrix(c(0.1,0.2,1.0,0.0,0.0,0.5,0.3,
                 0.1,0.7,0.0,1.0,0.0,0.5,0.3,
                 0.8,0.1,0.0,0.0,1.0,0.0,0.4), nrow =3, byrow = TRUE)
topconv <- cornerSort(data, 3, 10)