I propose that we add a formula to Calc that returns the value only if it's positive. I've seen plenty of spreadsheets where the value of a calculation is only useful if it's positive, otherwise it's considered to be zero. Currently, one must use IF() functions and repeat the value being tested. I imagine that it would look something like this:

Function IfPositive(value, Optional default)
   If value > 0 Then
      IfPositive = value
   ElseIf IsMissing(default) Then
      IfPositive = 0
   Else
      IfPositive = default
   End If
End Function


And similarly, an IfNegative() function for anyone who may need it. A function like this would really help to simplify these types of formulas. One example is when calculating tax credits:

=IF(273 - IF(C1 - C2 > 0, C1 - C2, 0) * 0.04) > 0, 273 - IF(C1 - C2 > 0, C1 - C2, 0) * 0.04), 0)

Would simplify to:

=IFPOSITIVE(273.00 - IFPOSITIVE(C1 - C2) * 0.04)

I'm not totally sure if IfPositive()/IfNegative() is the best name for this type of function, so any comments on that would also be appreciated.