5

ECOM II

Note: the Monte Carlo menu is disabled until you perform an Ordination analysis.

When the program is started, you will be presented with a blank working area.

Assuming that you have data already prepared, from the Biological File menu choose

Open Biological and from Environmental File menu choose Open Environmental to

load existing data sets. Once a data set is loaded or a new data set created, the

window will be filled by a form with tabs labelled Sample/Species Data,  Working

Sample/Species Data, Environmental Data, Working Environmental Data, Summary

and Scatter Plot. The Raw Data forms, Sample/Species Data and Environmental Data

show the data loaded from disc. The Working Data grids show the data sets upon

which the calculations will be performed, Summary gives statistics for the data sets

and Scatter Plot lets you select variables to plot as 2 and 3 dimensional graphs. You

can switch between the different forms by clicking with the mouse on the tabs.

Initially, the Raw Data and Working Data will display the same values. Once a

transformation or some other adjustment has been applied to the data (for details see

below) the Working Data grids will display the adjusted data.

Obtaining help

Opening a data set

Demonstration data sets

Creating and editing a data set

Maximum size of the data set and computation speed

Printing and exporting your results

Graph display options

Zooming and panning on graphs

1.3

Improvements to Version 2.0 of ECOM

A number of significant improvements have been incorporated into Version 2.0.

Most importantly, new array handling technology has been built into the code to

enable data matrices of virtually any size to be handled. Calculation speed has also

been improved and even very large data sets can be handled with ease.

The range of methods available has also been increased, with the introduction of

Forwards and Backwards Stepwise regression.

1.4

Quick quide to running a data set

1.

Prepare the biological data set using a spreadsheet such as Microsoft Excel. The

data are arranged with samples (quadrats, or stations) as columns and species

(variables) as the rows. Give a title to each sample and species. Values can be

real or integer and place 0 (a zero) in all localities where a species was not

recorded. This can be automated by searching for blanks in Excel and making

them 0. Make sure you use a zero and not a capital  0 !

2.

Save this array as a .csv (comma delimited text) file from the Excel Save As

menu. Take care if using Excel that the work sheet does not hold any other data

or this will be included in the csv file.

3.

Prepare and save the environmental (physical) data set in a similar fashion to the

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