0 on a logarithmic axis

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E - 28 Aug 2007 17:28 GMT

I have a chart I am trying to plot data from 0ng to 1.9mg and a logarithmic
scale works beautifully except that I have an important value at a 0ng (the
start of my curve). Is there anyway to make the 0 value show up in a
logarithmic scale?

Thanks,
-E

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David Biddulph - 29 Aug 2007 01:17 GMT

No. Zero on a log scale would be at minus infinity. You could change the
value from zero to something very small (10^-n g), but how small you make it
will affect where it appears on the log scale; that's how logarithms work.

Signature

David Biddulph

>I have a chart I am trying to plot data from 0ng to 1.9mg and a logarithmic
> scale works beautifully except that I have an important value at a 0ng
[quoted text clipped - 4 lines]
> Thanks,
> -E

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E - 29 Aug 2007 15:40 GMT

I had a feeling that is what the answer would be. If I do change the value
of my 0 to 10^-n, is there a way to remove the logs I do not need (ie go from
.00001 to 1 without the huge space in between)?

> No. Zero on a log scale would be at minus infinity. You could change the
> value from zero to something very small (10^-n g), but how small you make it
[quoted text clipped - 7 lines]
> > Thanks,
> > -E

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David Biddulph - 30 Aug 2007 00:09 GMT

You could probably use a broken axis:
http://peltiertech.com/Excel/Charts/BrokenYAxis.html

Signature

David Biddulph

>I had a feeling that is what the answer would be. If I do change the value
> of my 0 to 10^-n, is there a way to remove the logs I do not need (ie go
[quoted text clipped - 16 lines]
>> > Thanks,
>> > -E

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E - 04 Sep 2007 17:42 GMT

Thanks David!

> You could probably use a broken axis:
> http://peltiertech.com/Excel/Charts/BrokenYAxis.html
[quoted text clipped - 18 lines]
> >> > Thanks,
> >> > -E

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