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7.13 Computed Cell References

     

Several NExS functions such as @CELLREF and @RANGEREF return a result that is itself a cell reference or range reference. This is a powerful facility, but it must be used with caution because NExS can not take these indirect references into account when determining the order of recalculation. The same caution applies to constraint expressions used in conditional statistical functions. As a rule, cells that are indirectly referenced by a function are not automatically recalculated. NExS provides a special construct to force a recalculation, referred to as an explicit dependency.

NExS does not recalculate the spreadsheet unless explicit dependencies have been changed, so you may need to force recalculation if you change the value of a cell that is referenced only indirectly through a function.

For example, suppose you want to count the numeric values in the range C3..J100 that fall within the limits specified in cells A1 and A2. The NExS formula to compute this is
@CCOUNT(C3..J100,#>A1 && #<A2)  
This formula will correctly count the numeric values in the range C3..J100. However, if you change the value in A1, NExS will not automatically recalculate the result, because A1 is referenced only indirectly through the constraint expression.

   

Using explicit dependencies to circumvent the limitation described above, if you entered the formula below in the form
@CCOUNT(C3..J100,#>A1 && #<A2)\A1\A2  
NExS would take into account the dependencies on A1 and A2 and update the spreadsheet just as you expect.

Another approach is to construct the condition string with an expression that references the cells directly. For example,
@CCOUNT(C3..J100, @STRCAT("#>",A1,"&&#<",A2))  
In this example, A1 and A2 are directly referenced and thus will properly trigger recalculation.


Explicit Dependency is described in more detail in Chapter 6, Calculations.


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Next: 8 Defining the Appearance Up: 7 Built-in Functions Previous: 7.12.2 Using Operators with

NExS User's Guide, Version 1.4.5
Grey Trout Software
11 April 1999