...from the Microcomputer Power website.

by Hugh G. Gauch

MS-DOS^TM adaptation by Charles L. Mohler

ORDIFLEX is a flexible program for four ordination techniques:

* weighted averages (WA)

* polar (Bray-Curtis) ordination (PO)

* principal components analysis (PCA)

* reciprocal averaging (RA)

A simple control line is used to select the computations desired for each data set. The format of the input species-by-samples data matrix is flexible and ORDIFLEX can apply elementary editing and common data matrix transformations. Species and samples may be identified by user-supplied 8-character alphanumeric names.

Ordination results may be graphed. Also, the data matrix can be printed as one-character decile values, with rows and columns arranged according to the rank of ordination scores.

WA and PO may be done by species or by samples: PCA and RA do both simultaneously, PO endpoints may be specified by the user, or supplied automatically by three alternative procedures.

Any number of ordinations may be applied in a single run to any data set, but only one editing and transformation is allowed for each data set (although it may be read in several times to allow several transformations).

The manual includes a chapter on ordination theory, explaining the purpose and process of ordination, with recommendations on all steps from collection of field data to final presentation of results.

The ORDIFLEX manual also describes 24 supplementary data sets for use in gaining familiarity with RA results for a variety of data set properties.

The MS-DOS^TM executable module is dimensioned for 100 Species, 270 Samples, 27,000 array elements.

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