ncutpp

PURPOSE

Minimum normalised cut projection pursuit

SYNOPSIS

function [optHP, idx, spindex] = ncutpp(Data, pars, labels, colours)

DESCRIPTION

Minimum normalised cut projection pursuit
[OPTHP, IDX, SPINDEX] = NCUTPP(X, PARS, LABELS, COLOURS)

 Inputs:
    (X): Data matrix
    (PARS): Structure containing all parameters of ncutdc() algorithm
    (LABELS): True clusters; only used for visualisation (optional)
    (COLOURS): Colormap matrix: only used for visualisation (optional)

 Output:
    (OPTHP): Minimum normalised cut hyperplane (if more than one initial projection vectors
        are used then the one that maximises the splitting criterion pars.split_index())
    (IDX): Binary cluster assignment {-1,1}
    (SPINDEX): Value of splitting index criterion

CROSS-REFERENCE INFORMATION

This function calls:

fixLabels Enforces cluster labels to be in the range 1:K
ifelse Shorthand for ternary operator: if-then-else
isOctave Determines whether the environment is GNU Octave (returns TRUE) or MATLAB (returns FALSE)
pcacomp Returns the principal components of (X) specified in vector (index)
f_df_ncut Function value and derivative of minimum normalised cut projection index
f_ncut Function value, split point, and cluster assignment for minimum normalised cut projection index
nchp Minimum Normalised Cut Hyperplane (inherits from HP class)

This function is called by:

ncutdc Minimum Normalised Cut Divisive Clustering
nchp Minimum Normalised Cut Hyperplane (inherits from HP class)
ncuth Minimum Normalised Cut Hyperplane