STATISTICS

Genstat for Windows 9th Edition

Genstat for Windows 9th Edition - VSN International

26 October 2006

VSN International

Reviewed by Felix Grant

This latest version of VSN's heavyweight flagship, a substantial update like all its predecessors, is everything that users would expect from its long development history rooted in practical experience at the coalface. It also builds on recent work to dramatically enhance the facilities for exploratory users.

The worksheet, already growing progressively more flexible and more sophisticated with each release, has flowered. Sheets are now bound into tabbed multi-page workbooks (as in most generic standalone spreadsheets), which dramatically expands the scope for interactive workflow and logical project management. Stored in a new compressible GWB file type, and handled through a single 'Book' menu, these can be split, moved, reordered, intelligently read from and written to Excel workbooks. Sheets can be simultaneously imported from heterogenous sources, written out to single sheet Genstat GSH files (or a range of other options), dragged and dropped between books, and so on.

An enlarged section of a 3D scatterplot is examined over its associated Genstat 9th Edition input and output panes (background, right). At screen left, with vector data expanded, is the Genstat workbook structure tree. Larger image

Calculation formulae can be used (but are not stored) in entering individual cell values for a range of common functions. The formula syntax starts with an Excel-friendly '=' sign, but follows Genstat conventions thereafter – using '**' rather than '^' for power, for example. Along with the workbook come refinements in the user interface and extensions to interoperability. The latter includes expansion of file import formats, as might be expected (including those stored within ZIP archives), but also an interesting ability to run an external R script and read back the resulting output for further use.

As always, but even more so than in previous versions, power available through GUI menus has grown. Picking examples purely according to my own unashamedly personal interests, there are diversity measures and a very useful set of survey analysis tools under summary statistics, while species abundance plots (abundance/biomass comparison, k-dominance, or Whittaker rank/abundance) and distributions join the Graphics and Stats menus respectively.

As with any comparable product in this class, full power comes with use of the underlying command language for which the GUI is a front end. All in all, the new Genstat Server (9·1) lists '2 new directives, 64 new procedures and 2 new functions'. Categorised under about 30 headings, these include further development of mixed models treatment to analysis of similarities, continued development of GLM methods and a differential evolution Markov chain algorithm. A significant chunk of the new procedures list represents a particularly strong attention to microarrays.

All the exploratory features already mentioned are of course available from the command line. A 12-option FSPREADSHEET procedure and five-option, three-parameter SPLOAD directive provide detailed command line control over loading of data into the workbook structure. External R script handling is through eight-option, five-parameter RXGENSTAT controls. Five EC* (ECFIT, ECNICHE, etc) procedures manipulate the abundance and diversity features, while an SV* set gives entry to survey analysis.

The general pattern of Genstat upgrades has always been for to offer even greater expansion than the last, and that pattern is maintained here. After an intensive couple of weeks using it in labs, factories and rocky spray-blown beaches, I'm very impressed.

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