Fixed range stops working when multiple axes are added

plotly.js
1

Hi!

I have some scatter chart which uses the range/autorange feature only for one end of the y-axis. The upper end range is set to 100, while to lower end should be dynamically/auto-ranged.

Here is the relevant code for the axis:

var layout = {
    // ...
    yaxis: {
        range: [null,100],
        autorange: 'min'
    },
    // ...

This is working fine, if only a single line is shown in a chart. As soon as I add a second line with its own y-axis, the first line seems to have autorange enabled for both ends of the axis, i.e. the range: [null,100] configuration is ignored.

I’ve created a simple demo on CodePen to show the behavior. Initially only a single line is shown and the y-axis ranges up to 100. As soon as you enable the second line and axis by uncommenting line 8, the range for the first y-axis changes unexpectedly.

Is this a bug or do I miss something that needs to be set to keep the desired behavior?

Thx,
martin

BTW, I’m using Plotly.JS version 2.35.2.

2

I’ve found an existing bug report, which has the same problem in another use-case. Probably same cause.

3

I’m not sure I understand well but I think this is what you are looking for, just comment out the two autoranges and the anchor: ‘free’ and uncomment your second axis

1 Like
4

Thanks @Saratoga!

The anchor: 'free' was the problem. Removing this entry solves the problem and the autorange-feature is working as expected. (The two autorange entries were not necessary but didn’t harm.)

Not sure why I had the anchor: 'free' in the example. It was probably left over from other experiments.

Anyway, could you please explain the anchor property to me and why this effects the autorange? The documentation isn’t of much help. It only references the position property.

Many thanks,
martin

5

Hi again!

The solution proposed by @Saratoga only works, if I have at most two y-axes. Once a third axis is added, I need anchor: 'free' to position the axes correctly.

I’ve created another CodePen to show the problem: at first two traces on separate y-axes are shown. Range is always set to [null,200], which means upper bound is 200 while lower bound is dynamically.
As soon as you enable a third trace with a third axis (by uncommenting line 10), the range of the first two axes changes unexpectedly.

The question remains: why does anchor: 'free' affect range/autorange? Is this a bug?

Many thanks for your help, Martin.

6

I created a bug-report for this issue: