Release Date: 12-April-1995
Affected Versions: Neuralyst 1.40b or earlier
Symptoms: Excel 4.0 allows multiple worksheets, each containing a Neuralyst neural network and related working area, to be defined within a workbook and each worksheet could be reloaded by the Neuralyst Reload Network command. However, an Excel 5.0 workbook with multiple worksheets cannot be reloaded in the same way. Attempts to reload some worksheets which were previously initialized, causes the message “Worksheet ... must be initialized.”
Problem: Neuralyst identifies its neural network configuration data and neural network weights as the “Working Area” of a Neuralyst/Excel worksheet. The Working Area is identified by giving it an Excel worksheet name, “NWTL”. This naming occurs when the Init Working Area command is performed. Reload Network looks for the NWTL name on the active worksheet to identify the Working Area. Under Excel 4.0, the NWTL name is tied to a worksheet, and different worksheets maintain individual name lists. Under Excel 5.0, the NWTL name is tied to a workbook and only one name list is maintained per workbook. Thus, whenever an Init Working Area command is performed, which includes the definition of the NWTL name, any previous definition of the NWTL name in that workbook is replaced, preventing future Reload Network commands from working correctly on the superceded Working Area. Solution: Under Excel 5.0 it is necessary to maintain separate neural networks under separate workbooks.