Vertex Component Analysis Unmixing Algorithm

Source: R/vca_nascimento.R

This algorithm is based on the geometry of convex sets. It exploits the fact that endmembers occupy the vertices of a simplex. Intended to be called from vca.

vca_nascimento(data)

Arguments

data

Data matrix. Samples in rows, frequencies in columns. This function expects data to be already dimension-reduced (for example with vca_dr). The number of endmembers is inferred as ncol(data).

Value

A list which contains:

  • indices: indices of endmembers in extraction order.

  • projection_vectors: projection vectors (row-wise) used in each iteration, included only when debuglevel >= 1.

Both elements are returned in the same order as the endmembers are extracted.

References

Nascimento, J.M.P. and Bioucas Dias, J.M. "Vertex component analysis: a fast algorithm to unmix hyperspectral data," Geoscience and Remote Sensing, vol. 43, no. 4, pp. 898-910, April 2005, doi: 10.1109/TGRS.2005.844293