allowDecimals: false ignored with flat data

[drmrbrewer]

Expected behaviour

Setting allowDecimals: false on the yAxis should result in integer axis labels.

Actual behaviour

With flat high-precision data, this doesn't work.

Live demo with steps to reproduce

http://jsfiddle.net/xhs3fonh/2/

Affected browser(s)

Any, I assume.

[pawelfus]

Workaround:
Use yAxis.minRange, demo: http://jsfiddle.net/xhs3fonh/4/

Short explanation: it's not caused by high precision as in the title, but it's related to all points having the same value. If only one value will be a bit different, it will work correctly: http://jsfiddle.net/xhs3fonh/5/

[drmrbrewer]

@pawelfus OK. So this is recognised as a bug that will be fixed... hence no need for the workaround in future version?

[pawelfus]

I think this should be closed as duplicate of #5956. I know this is the report for allowDecimals, but under the hood it's issue with extremes for flat data. Also workaround from #5956 works for this issue: @http://jsfiddle.net/xhs3fonh/7/

It should be configurable, so we can choose if we want to get flat data in the middle of a chart, with just one tick, or we want to generate N-ticks anyway.

[TorsteinHonsi]

It should be configurable, so we can choose if we want to get flat data in the middle of a chart, with just one tick, or we want to generate N-ticks anyway

It looks like we've already got that option - by setting minRange. Do you think that's enough? In that case we just need to communicate it better, add it to the docs in appropriate places etc.

[pawelfus]

It depends if we talk about allowDecimals or general solution? For allowDecimals it's perfectly fine, as we know the minimum range (one unit, without decimals), but not when considering extremes for a flat data. User may not know which minRange will be fine, let's consider these two examples:

• http://jsfiddle.net/xhs3fonh/7/ (minRange: 1 is fine here)
• http://jsfiddle.net/xhs3fonh/8/ (minRange: 1 won't work nicely)

Both examples can be created using the same config etc. on the same page (just data from backend can be different).

[TorsteinHonsi]

User may not know which minRange will be fine

The point with flat data is that there is no way that Highcharts can guess what the preferred scale is, that's why we chose to present it with one single tick in the first place. (Previously we added integer ticks if I remember correctly). But with using minRange, we offer the user an option to take some control and add a scale.

[drmrbrewer]

Referring to my original post, my surprise was that with allowDecimals set to false and yet I was still seeing decimals on the axis label. At least where allowDecimals is set to false, you know that instead of just a single 1.3333333 as in my original example, you just put two ticks at 1 and 2 either side. With allowDecimals set to true I wouldn't have been surprised at the lack of scale (just a single tick), and if it bothered me I would probably have found minRange as the solution. So for me, the only issue that needs fixing relates to ensuring that allowDecimals = false always has the expected effect... i.e. no decimals on the axis, ever... shouldn't need the minRange workaround because allowDecimals = false should already impose that workaround.

[TorsteinHonsi]

Yes, I agree to that conclusion.