Talk:Logarithmic scale

Color of graphs are hard to see
Please use colors that can be distinguished. The red and greens that were chosen are hard to see. Use a bright lime color or yellow instead dark green please.

Other topics
I believe I have made the appropiate changes to the last part of the article. I haven't altered the actual content, only the writing style. I have taken out references like I and you and replaced it with adequate substitutes, I would hope the writer could check to make sure I haven't done anything wrong though. A happybunny 16:47, 12 February 2007 (UTC)

I just cleaned up the last part of the article further in the interest of readability, spelling and grammar. I've rearranged a few sentences to be ore concise, and adjusted the maths and layout so that it's all easier to follow. TaintedCherub 14:14, 18 February 2007 (UTC)

The example given for accurate determination of values on a logarithmic axis ie, (10^0.5)*10 would be more clear if it used a number whose nearest decade line with lower value is not 10. For instance, if the example were

Example: What is the value that lies halfway between the 1 and 10 decades on a logarithmic axis? Since it is the halfway point that is of interest, the quotient of steps 1 and 2 is 0.5. The nearest decade line with lower value is 1, so the halfway point's value is (10^0.5)*1.

there would be no confusing of the exponent base and the next lower decade line 24.6.96.96 14:09, 3 May 2007 (UTC)Miles Libbey

if its possible i think a blank logarithmic and half-logarithmic pages would have been nice add to the bottom of the article, can be very handy to some.

I've added a major section on Logarithmic and Semi-Logarithmic Plots and Equations of Lines. The discussion and examples are from text I've developed and used a great deal in my own work and that I think further ellucidates graphing on logarithmic scales. Odarren 09:11 14 June 2007 (UTC)

help please!
It would be great if someone could make this page more accessible to non-mathematically oriented persons by explaining in layman's terms how to calculate log points and adding a table with the correspondence between log points and percentages. —Preceding unsigned comment added by 128.103.142.186 (talk) 19:49, 28 February 2008 (UTC)

I cant understand a word of this. help? —Preceding unsigned comment added by 24.148.4.137 (talk) 23:05, 31 December 2008 (UTC)

The logarithmic interpolation is very difficult to follow, both in mathematical reasoning and paragraph spacing format. Also, it only covers interpolation based on physical measurements of a graph, not coordinates, and even then only includes a worked example without a general formula or simple instructions how to apply it to a different case. —Preceding unsigned comment added by 128.158.1.166 (talk) 20:31, 21 December 2009 (UTC)

If this article were more elegantly written I think it would be much easier to understand. Yes, it is a difficult subject but the writing here makes it more so. SG —Preceding unsigned comment added by 75.48.2.10 (talk) 20:13, 2 March 2010 (UTC)

Why can't I understand anything? Maybe the words used should be simplified to everyday language instead.... —Preceding unsigned comment added by 24.148.4.137 (talk) 23:05, 31 December 2008 (UTC)  —Preceding unsigned comment added by 24.87.9.243 (talk)

No mention of finance?
Log plots are extremely common in finance as constant Rate of returns show up as straight lines.DavidRF (talk) 23:01, 9 October 2008 (UTC)

centi-neper
See Reference_desk/Mathematics (from May 13, 2010) on the need for a logarithmic substitute for the percent. Bo Jacoby (talk) 05:04, 17 May 2010 (UTC).

Logarithmic and semi-logarithmic plots and equations of lines
I can't follow the discussion in the Logarithmic scale section and the 1 dimensional graphs don't make any sense to me. I'm writing new text to discuss how different functions appear when plotted on the different logarithmic scale graphs:

-- Autopilot (talk) 17:44, 26 June 2010 (UTC)

In the first part of this section there appears to be some confusion of the bases of logarithms. For example, I believe that this text:

"In the first case, plotting the equation on a semilog  scale (log Y versus X) gives: log Y = −aX, which is linear."

should make it clear that the logarithm is to base e and not to base 10. I haven't corrected this because I may have misunderstood the concept. If you know more about logarithms than I please edit the text to make explicit references to the bases of the logarithms.

-- Iain Robinson

Not True Iain if you tell that to an engineer you will most likely get laughed at. Entire engineering department depends on a base ten Log-log scale. And a Log-Log scale or semi-log can be of any base the principal is the same. I guess it just needs to be a more general explanation with a base ten example. In engineering base ten is used far more often than base e. dB, dBm, dBmV, dBuV, dBmA, dBuA, etc. Dominate mil standards and industry standards when you are talking about cross-talk, radiated susceptibility, conducted susceptibility, radiated emissions, conducted emissions, shielding effectiveness, signal integrity, etc. --Ervin Seferi (Math, Physics major and Test Engineer Profession) — Preceding unsigned comment added by 69.174.58.124 (talk) 11:30, 21 July 2011 (UTC)

Definition is wrong
The current incorrect definition:

A logarithmic scale is a scale of measurement using the logarithm of a physical quantity instead of the quantity itself.

Correct suggestion:

A logarithmic scale is a scale of measurement where the labels are placed at distances proportional to the differences between their logarithms. Since the logarithm of 1 is zero, this implies that the distance between 1 and x is proportional to the logarithm of x.

Also, I don't like this paragraph, I think it is confusing. What size are the increments, it doesn't mention that they are equidistant, and what exactly is a "unit increase"? :

'''A simple example is a chart whose vertical axis increments are labeled 1, 10, 100, 1000, instead of 1, 2, 3, 4. Each unit increase on the logarithmic scale thus represents an exponential increase in the underlying quantity for the given base (10, in this case).''' — Preceding unsigned comment added by 187.105.21.75 (talk) 17:00, 29 September 2011 (UTC)

PITCH BALL
PITCH BALL A GAME JUST LIKE CRICKET — Preceding unsigned comment added by 61.3.175.133 (talk) 15:23, 31 March 2014 (UTC)

semi logarithmic hyphen
According to http://www.merriam-webster.com/dictionary/semilogarithmic there is no hyphen. Sometimes there's a hyphen and in this article there is a space. Which is correct? QuentinUK (talk) 07:02, 23 August 2015 (UTC)
 * Sounds like a question for the MOS. Dondervogel 2 (talk) 08:43, 23 August 2015 (UTC)

lead paragraph
The lead paragraph notes that "A logarithmic scale is a nonlinear scale used when there is a large range of quantities." Even though my fundamentals of psychology classes are part of the distant past I still remember that some quantities -- such as sound and brightness -- are measured on logarithmic scales not only because of the potentially large range of values but also because human perception of these phenomena is itself logarithmic. For example, doubling the amount of sound energy will not create a sound twice as loud...maybe just 150% louder...I forget the specific numbers. Some of the other phenomena, such as earthquakes, might behave similarly -- doubling the input doesn't necessarily double the output. I think it would be interesting and valuable to explain that using a logarithmic scale isn't just a matter of numerical convenience but can be directly linked to the matter at hand. PurpleChez (talk) 18:08, 23 March 2017 (UTC)

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Opening paragraph is possibly self-contradictory
In the opening paragraph it states:

"It is arranged so that the logarithm of the value represented by each equidistant mark on the scale is equal to the logarithm of the value at the previous mark plus a constant. This means that the value represented by each equidistant mark on the scale is equal to the value at the previous mark multiplied by a constant."

Can both of the statements in bold above be true? Since I don't know what applying "the logarithm of the value" actually means, I can't say for certain. To be clear:

Does repeatedly applying the logarithm of a value plus a constant equate to multiplying the said value by a constant? — Preceding unsigned comment added by HappyGod (talk • contribs) 02:36, 16 March 2020 (UTC)
 * I just reviewed the lede and it looks OK to me re accuracy. Perhaps could be clearer by including a simple and familiar example (octave scale). Dondervogel 2 (talk) 07:30, 16 March 2020 (UTC)

Logarithmic units -- motivation
This section is in content practically unchanged from the very first version of Logarithmic units from 2005, merged into this article in 2018. I am a physicist, Boltzmann's definition of entropy is something I am very familiar with, but I do not think that the content would contribute to anybody's understanding. I think the first paragraph (two sentences) under the heading "Logarithmic units" here define the concept quite clearly enough. And actually, what it leads to is simply wrong: Boltzmann's constant is not what relates ln(W) (depending on Euler's number e) to something "more fundamental", without a particular choice of unit. No, it relates ln(W), which in itself is quite as fundamental as one would like to get, to something much more actual, namely the entropy, which you can use to construct steam engines.

The section seems very much like how the original author personally understood this concept. It does not look like how a general interested reader would go about understanding that. Note also that there is not a single reference here. So I would strongly propose to delete that section. Can anybody make an argument why it would be good to preserve it? Seattle Jörg (talk) 15:18, 4 May 2021 (UTC)


 * I went ahead and deleted it. Seattle Jörg (talk) 22:21, 13 June 2021 (UTC)