Make log scale configurable

[oc37ejuc]

Hi there,

would it be possible to make the axis log scaling base configurable?

I have some data sets that need to be plotted with a logarithmic scale, and due to the nature of the data, base 10 does not make sense.

Kind regards,
oc37ejuc

[etpinard]

Yeah, we could add a new axes type e.g. xaxis.type: 'ln'

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This won't be a priority for us in the near future, but we'll gladly look at a PR from the community.

Referencing a similar request: #221

[alexcjohnson]

This doesn't need to be a different type, just a new attribute (base?) to change how ticks are drawn. The tricky thing here will be to find a nice algorithm for choosing tick values for arbitrary range / nticks combinations, and it might be too much to ask that this also work well for an arbitrary base, perhaps it's more realistic to make the framework and separate algorithms for each specific base someone needs.

[ghost]

Although we just need it for the base 2, the approach using an arbitrary base value might prove useful to others. Unfortunately I can't code any Java*, but I can offer some suggestions on the tick-drawing algorithm:

Major ticks are drawn at all multiples of base in the range.

If current_major and next_major are the positions of the current and the next major ticks, between which a total of n minor ticks should be drawn then the minor ticks should be placed at
current_major * nearest_integer(factor**n_tick), where n_tick is the number of the current minor tick and factor is the n+1th root of base.

[pewinski]

I've step into similar problem when developing for my client.

What they want is a way to represent a curve using 10 based log scale of axis (including values lower or equal to 0, similarly to symlog. These are cutoff in current implementation of logarithmic axis).

[Berkmann18]

It would be nice to use log2 or ln instead of log10.

[archmoj]

It would be nice to use log2 or ln instead of log10.

And the natural logarithm too?

[Berkmann18]

@archmoj

And the natural logarithm too?

That's what ln is.

[esternin]

I think adding a base value to the call is the best. I would also allow for any number +/-3% of e to result in ln, but outside of this range, treat base numbers as exactly the base that is desired.

xaxis: {type: 'log', logbase: 2.7}

would be the way to get ln. The default value should be 10 for the logbase.

The scaling of the axes (min,max,step) should be in logs of values, if type=='log'. For example 32=2^5, so to cover max(x)=32 the range of x should have the upper limit of 5.

That's my vote.

[gvwilson]

Hi - this issue has been sitting for a while, so as part of our effort to tidy up our public repositories I'm going to close it. If it's still a concern, we'd be grateful if you could open a new issue (with a short reproducible example if appropriate) so that we can add it to our stack. Cheers - @gvwilson

[esternin]

Closing issues without addressing them is one way to shorten the issues ' list. Perhaps not the best one. This is (was) an enhancement suggestion. The suggestion contains examples of syntax being proposed. I did not see support or arguments against. Repeating this as a new issue will not change that. But you are the boss, so close it if you want.

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On June 11, 2024 1:02:00 p.m. EDT, Greg Wilson ***@***.***> wrote: Hi - this issue has been sitting for a while, so as part of our effort to tidy up our public repositories I'm going to close it. If it's still a concern, we'd be grateful if you could open a new issue (with a short reproducible example if appropriate) so that we can add it to our stack. Cheers - @gvwilson -- Reply to this email directly or view it on GitHub: #2362 (comment) You are receiving this because you commented. Message ID: ***@***.***>

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[gvwilson]

Thank you for your comment - as mine said, we are trying to clean up our public repositories (which currently have over 3500 open issues, some going back more than eight years), and there had been no activity on this issue in four years. It's not on our roadmap, but if someone would like to contribute a pull request we will review it as quickly as we can.