Linear spacing of points in log scale

  • Thread starter Thread starter Ron Cüppers
  • Start date Start date
R

Ron Cüppers

Hi,

I am searching for a formula to derive linear spacing in a log chart. The
spacing between 1 and 2 in log scale much more than between 8 and 9. To
derive a 'smooth' graph I need more points at low values of the log scale.
For a sufficient number of points for the x-axis i am searching for a
formula to derive this.
 
Ron,

It's raising a number to arithmetically spaced powers that will result in
such spacing on a log scale.

Try this. Put a bunch of arithmetically spaced numbers in column A, and the
following in B, copied down:

=10^(A1/$C$1)

Example:
Column A contains 1,2,3...
Column B contains the formula
C1 contains 10
 
Ron,

It's raising a number to arithmetically spaced powers that will resultin
such spacing on a log scale.
Click to expand...

Spot on, Earl. To expand a little bit, you can raise powers of any
number. For example, 2^n (1,2,4,8,16,32,...) are equally spaced on a log
scale. That's true of any log scale and any basis; pi^n is equally spaced
on a log-base-e scale.
 
Yup. The range of log numbers can be anything (arithmetically evenly
spaced), and the base number doesn't have to be 10 (even though the log
scale of the chart uses base 10). It just tilts the line when you use a
different base.


Earl Kiosterud
mvpearl omitthisword at verizon period net
-------------------------------------------

Ron,

It's raising a number to arithmetically spaced powers that will result in
such spacing on a log scale.
Click to expand...

Spot on, Earl. To expand a little bit, you can raise powers of any
number. For example, 2^n (1,2,4,8,16,32,...) are equally spaced on a log
scale. That's true of any log scale and any basis; pi^n is equally spaced
on a log-base-e scale.
 
Thanks both of you.

It helped a lot. I now have the formula and use it in VBA.

Thanks !!
 
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