Some trendlines cannot be calculated from data containing negative or zero values

Can this alert be turned off?

In Excel 2000, XP, and 2003, This message occurs when you modify data
that is charted with a Logarithmic, Power, or Exponential trendline, in
such a way that refitting the trendline would essentially require taking
logarithms of negative numbers. Since Excel's functions (other than a
few in the Analysis ToolPak, which is a 3rd party Add-In that only ships
with Excel) are all restricted to real values, what do you think Excel
should do instead of warning you that it cannot do what you have asked
it to do?

Jerry

Reo Grande wrote:

> Can this alert be turned off?

"Jerry W. Lewis" <post_a_reply@no_e-mail.com> wrote in message
news:41C5864A.80601@no_e-mail.com...
> In Excel 2000, XP, and 2003, This message occurs when you modify data
> that is charted with a Logarithmic, Power, or Exponential trendline, in
> such a way that refitting the trendline would essentially require taking
> logarithms of negative numbers.

With dynamic ingestion of data on 3 second intervals with occasional zero
values in the data set that are of no significance the warning is pointless.

>Since Excel's functions (other than a
> few in the Analysis ToolPak, which is a 3rd party Add-In that only ships
> with Excel) are all restricted to real values, what do you think Excel
> should do instead of warning you that it cannot do what you have asked
> it to do?

As per the original post I would like to turn the warning off because for my
purposes it is nothing more than an irritation.

Do you have a solution or are you just chastising?

Again, you are asking Excel to fit a trendline, in a situation that is
impossible (log(0)=-infinity). Excel is simply telling you that you
have posed an impossible situation under the specified model, and it
doesn't know what to do. Turning off the warning (which as far as I
know, is not possible) would still not resolve the basic problem that
Excel does not know what you want it to do.

>> ... what do you think Excel should do ... ?

In what sense is zero data "of no significance"? If they should be
ignored entirely, use #N/A instead.

Jerry

Reo Grande wrote:

> "Jerry W. Lewis" <post_a_reply@no_e-mail.com> wrote in message
> news:41C5864A.80601@no_e-mail.com...
>
>>In Excel 2000, XP, and 2003, This message occurs when you modify data
>>that is charted with a Logarithmic, Power, or Exponential trendline, in
>>such a way that refitting the trendline would essentially require taking
>>logarithms of negative numbers.
>>
>
> With dynamic ingestion of data on 3 second intervals with occasional zero
> values in the data set that are of no significance the warning is pointless.
>
>
>>Since Excel's functions (other than a
>>few in the Analysis ToolPak, which is a 3rd party Add-In that only ships
>>with Excel) are all restricted to real values, what do you think Excel
>>should do instead of warning you that it cannot do what you have asked
>>it to do?
>>
>
> As per the original post I would like to turn the warning off because for my
> purposes it is nothing more than an irritation.
>
> Do you have a solution or are you just chastising?