Hi. If I understand the question, the log of say -5 would be a complex
number.
1.609+3.14159 i

If A1 holds -5, then perhaps two ways...

=IF(A1<0,COMPLEX(LOG(ABS(A1)),PI()),LOG(A1))

or more simply the engineering function...
=IMLN(A1)

--
HTH. :)
Dana DeLouis
Windows XP, Office 2003


"Craig" wrote in message
...
im trying to use negative numbers with excel's natural log function, and
have
found it doesnt work the way im trying it anyway, has anyone out there
used
negative numbers with Excel's natural log function and any sucess?