Hi.

I am making a model in Excel which is takes data updates from an outside
source and then processes the information to develop charts on the data.
There are a lot of charts so I have developed the model to process the data
automatically as the data comes (down the sheet). This processing means that
there are formulas in place, waiting for the data to come in. I use a
=if(a1="","",<operation) notation to do it for me. If there is data then
the if statement is false and the data can be processed; if the data hasn't
arrived yet then instead of getting an error message you get a "".

This works fine and I have set up the graphs so that there is a little
leeway for additional data to come in and for the information to fit in the
array read by the chart. However, my problem is that when the data hasn't
arrived yet and Excel encounters "" in a cell (i.e., the if statement is
true), which to me means <blank or <empty, it reads it as a zero.
Therefore my nice charts have a large vertical line back down to zero at the
end of every data series.

One option is to redo the arrays of the chart whenever I use the model but
there are probably 200 charts so this is uneconomic! What I am looking for
is a way to deal with the formulas so the Excel reads my "" as <empty rather
than a zero. Has anyone come across this problem before? Does anyone know
how I might solve this problem?

Thanks for your help.

Tom