Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!motcid!derosa
From: derosa@motcid.UUCP (John DeRosa)
Newsgroups: comp.sys.mac.apps
Subject: Excel WARNING!!
Message-ID: <5924@crystal9.UUCP>
Date: 28 Feb 91 22:06:31 GMT
Distribution: comp
Organization: Motorola Inc., Cellular Infrastructure Div., Arlington Heights, IL
Lines: 42

I ran into a problem with Excel that I was sure was
a bug.  I was copying some cells from one spread sheet
into another.  I selected 20 cells, copy and then paste
and ended up with 30 cells in the receiving spread sheet.

THIS MAY SOUND SIMPLE ENOUGH BUT THE UNDERLYING PROBLEM 
CAN CAUSE SOME MAJOR LEAGUE CALCULATION ERRORS.

I finally determined what the problem was after hours of head 
pounding.  It all comes down to the mis-use of a feature of Excel.  

Most Excel users know that you can split the Excel window 
into 1, 2 or 4 windows.  This is done by clicking and 
dragging on the black strip just above the "up" arrow 
or the strip just to the left of the "left" arrow.

Another commonly used feature is changing
the width of a column by clicking and dragging the 
column boundry.  While this feature can change the height
of a row, it is seldom used as the height of a 
row is automatically adjusted depending on the font
point size.  (BTW, I have been told that V3.0 will have automatic
Column width)

THE PROBLEM is that a row or a column can be shrunk to 
ZERO WIDTH.  This makes a row or column disappear (visually) 
while still being active for copying and (worse) math.

If you perform a sum on a row of cells, this calculation will
include these invisible cells, throwing off your math.
This might not be entirely obvious if the calculations 
are complicated.  We found a $200,000 error in a $3,000,000
calculation caused by this problem, i.e. data was entered
twice as we thought the information was missing.

With a copy and paste, the invisible cells are copied and 
when pasted, appear in the receiving spread sheet.
-- 
=       John DeRosa, Motorola, Inc, Cellular Infrastructure Group          =
= e-mail:    ...uunet!motcid!derosaj, motcid!derosaj@uunet.uu.net          =
= Applelink: N1111                                                         =
=I do not hold by employer responsible for any information in this message =