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Unit: SDL_math2
Class: none
Declaration: function VertexCompAnalysis (Data: TMatrix; NEndMembers: integer; UsePCA: boolean; var EndMEstim: TMatrix; var EndMIx: TIntVector; var DProj: TMatrix): boolean;

The function VertexCompAnalysis performs a vertex component analysis (VCA) using the algorithm of Nascimento. The parameter Data contains the spectral data (rows are spectra of observations, columns are spectral wavelengths). NEndMembers specifies the number of expected endmembers. If the data is noisy you might consider to set UsePCA to true, which forces the algorithm to start on the scores of a principal component analysis. On return, the function delivers TRUE if everything's ok. In this case the following variable parameters are valid.

The matrix EndMEstim contains the estimated spectra of the detected endmembers. The vector EndMIx contains the indices pointing to the found endmembers (the indices refer to the rows of the Data parameter). Finally, the parameter DProj returns the projected data

Mathematical details can be found in the following research paper: J.M.P. Nascimento, J.M.B. Dias, "Vertex Component Analysis: A Fast Algorithm to Unmix Hyperspectral Data", IEEE Trans. Geosci. Remote Sensing, Vol. 43 (2005), pp 898

Last Update: 2015-May-17