Draw y axis in different ticks

[eromoe]

I don't see this feature in docs, so ask here.

For example, I create a scratter to show the percentage difference between real sale_count and my model predicted sale_count of some products :

--

percentage_difference = (predict_value - real_value)/real_value

Most of points mainly locate in 0 ~ 1 . (percentage 0% ~ 100% )
As we know, there are always some outliers in the data, some of them may exceed 10 .

So I want to display the plot y axis in : [-10, -5, -1, 0, 1, 5, 10]

500% ~ 1000% with length 1
100% ~ 500% with length 2
0% ~ 100% with length 3
0% ~ -100% with length 3
-100% ~ -500% with length 2
-500% ~ -1000% with length 1

I think this is an usual requirement.

[alexcjohnson]

Sounds like what you're interested in is a symlog / asinh transform as discussed in #221
Other arbitrary transformations (as well as symlog unless and until we add it to plotly.js) can be handled with custom tick labels - you can do something like:

• set the trace.y values to the transformed data
• provide the original data as part of trace.hovertext (or hovertemplate with the original data in customdata perhaps)
• use yaxis.tickvals/ticktext to label the axis according to the transformation

[etpinard]

Merging into #221

[zxdawn]

@eromoe I want the similar setting as yours: control the length for specific space. How did you deal with it at the end?