Spreadsheet programs are designed for the business community. As such, they tend to provide only a rudimentary set of built-in functions for the more common statistical calculations. Intex Solutions have developed a rather useful add-in called @STATS, that attaches to Lotus 1-2-3 or Symphony. When activated, it provides an additional 44 statistical functions for the arsenal. Once the files have been copied to the 123 subdirectory, @STATS can be set to be used on demand (/ A dd-in Attach ...) or automatically attached whenever the spreadsheet is loaded. @STATS works directly with the Lotus s preadsheet programming language and can not be used with others.

The operation is simple with @STATS functions used in exactly

the same manner as any other Lotus @FUNCTION. To calculate 121 simply enter @FACTOR(12). To calculate a percentile, you enter @PTILE(range, percent), where range is the location of the data and percent is the percentile value you want. For the median, the percent value is 50. Other @FUNCTIONS include a variety of

terms to calculate geometric means, harmonic means, skewness, kurtosis, slopes, intercepts, etc. You can interpolate between points on a graph or integrate the curve over an interval using Simpson's method.

A wide selection of range variables make it easy to calculate the counts, sums, averages and variances over selected intervals without using the often-confusing Lotus database functions. The @COUNTBT(range, value1, value2) function with one simple calculation gives the number of values in the data range with values that lie between the value1 and value2. To produce a histogram, you can define the bins with a number of @COUNTBT functions. This is much more efficient than going through the / Data Distribution sequence as these functions automatically recalculate each time you make a change. Several sets of @COUNTBT functions can be used to produce several histograms at the same time.

The only difficulty I encountered was in retrieving a spreadsheet, that included @STATS functions, without first

c hecking that @STATS was attached. Lotus did not recognize them and replaced them with ERR. To avoid this make sure
```@STATS is attached before you retrieve
any files that use it. A very minor
```

annoyance with @STATS is a tendency for its startup screen to obliterate the top half of the spreadsheet. This corrects itself the first time the screen is rewritten. A minor limitation in the calculation of factorials is that the function only operates to a maximum of 50!

As we have said in previous Chemputing reviews, it is the power of these add-ins that give Lotus the big edge over their competitors. @STATS is a valuable addition for anyone who uses a spreadsheet for scientific calculations.

@STATS: Add-in for Lotus 1-2-3 and Symphony. Intex Solutions Inc., 35 Highland Circle, Needham, MA, USA, Tel: 617-449-6222, Fax: 617-444-2319. MSLP: \$US 295.

Software/Hardware mentioned are trademarks of their respective developers.