% @(#)pca_tabl.hlq	17.1.1.1 (ESO-IPG) 01/25/02 17:16:32
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1990 European Southern Observatory
%.IDENT      pca_tab.hlq
%.AUTHOR     FM, IPG/ESO
%.KEYWORDS   MIDAS, help files, PCA/TAB
%.PURPOSE    On-line help file for the command: PCA/TAB
%.VERSION    1.0  28-AUG-1986 : Creation, FM
%----------------------------------------------------------------
\se
SECTION./TABL
\es\co
PCA/TAB							28-AUG-1986  FM
\oc\su
PCA/TAB  in_tab out_tab option row/col_anal ncols_table eigenvectors
	principal components analysis
\us\pu
Purpose:  Principal Components Analysis, Karhunen-Loeve expansion.

\up\sy
Syntax:   PCA/TAB in_tab out_tab option row/col_anal ncols_table eigenvectors
\ys\pa
          in_tab       = Input table name.
\ap\pa
          out_tab      = Output table name.
\ap\pa
          option       = Analysis option:
                         3 = PCA of correlation matrix (default);
                         2 = PCA of covariance matrix; 
                         1 = PCA of sums of squares and cross-products matrix.
\ap\pa
          row/col_anal = Row/column analysis (R - default - or C;
                         note that all results are detd., but that output is 
                         produced for either rows or columns (cf. so-called 
                         "Q-" or "R-mode" factor analysis).
\ap\pa
          ncols_table  = Number of columns in output table (no. of
                         principal components). Defaults to 3.
\ap\pa
          eigenvectors = Eigenvectors output table name (defaults to none).
\ap\no
Note:     none

\on\exs
Examples:
\ex
          PCA/TAB INTAB OUTAB
          carries out a PCA on all columns of INTAB, using standardization
          of rows (leading to PCA on correlations), and producing output
          projections on 3 principal axes in OUTAB.  A keyword is written
          in OUTAB containing eigenvalues.
\xe \sxe