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Default 0 on a logarithmic axis

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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Thumbs up Answer: 0 on a logarithmic axis

Hi E,

I understand your concern about plotting a value of 0 on a logarithmic scale. Unfortunately, it is not possible to plot a value of 0 on a logarithmic scale as the logarithm of 0 is undefined. However, there are a few workarounds that you can try to display the 0 value on your chart.

One option is to use a small non-zero value instead of 0, such as 0.001 or 0.01. This will allow you to plot the data on a logarithmic scale and still display the important value at the start of your curve. You can label the axis to indicate that the value is not exactly 0.

Another option is to use a broken axis. This means that you can break the y-axis at a certain point, such as 0, and display the values below the break separately from the values above the break. This will allow you to display the 0 value on the chart without distorting the rest of the data.

To create a broken axis in Excel, you can follow these steps:
  1. Select the chart and go to the Format tab in the Chart Tools section of the ribbon.
  2. Click on the Axis dropdown menu and select the axis that you want to break (usually the y-axis).
  3. Click on the Format Selection button at the bottom of the dropdown menu.
  4. In the Format Axis pane that appears on the right side of the screen, scroll down to the Axis Options section and check the box next to "Axis breaks".
  5. Set the Minimum and Maximum values for the axis below the break and above the break.
  6. Adjust the spacing and formatting of the axis as needed.

I hope these options help you to display your data effectively. Let me know if you have any other questions or concerns.
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Default 0 on a logarithmic axis

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.
--
David Biddulph

"E" wrote in message
...
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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Default 0 on a logarithmic axis

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)?

"David Biddulph" wrote:

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.
--
David Biddulph

"E" wrote in message
...
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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Posts: 8,651
Default 0 on a logarithmic axis

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

"E" wrote in message
...
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)?

"David Biddulph" wrote:

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.
--
David Biddulph

"E" wrote in message
...
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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Posts: 40
Default 0 on a logarithmic axis

Thanks David!

"David Biddulph" wrote:

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

"E" wrote in message
...
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)?

"David Biddulph" wrote:

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.
--
David Biddulph

"E" wrote in message
...
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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