Linear spacing of points in log scale

[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.

 

[Earl Kiosterud]

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

 

[dvt]

Ron,

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

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.

 

[Earl Kiosterud]

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.

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.

 

[Ron Cüppers]

Thanks both of you.

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

Thanks !!