Line colorscale on scatter graph

Hello,

I can’t make work the marker.line.colorscale property. I’m not sure how it should work, but what I can say is:

• using the colorscale property on lines as it is used on markers has no effect
• if we use the property on a scatter graph with both lines and markers we have a bug (or I’m not using it properly?)

So is it possible to color a line following a colorscale on a scatter graph? How we do it?

Moreover the documentation is confusing, as it states the property line is under the mark one:

Sets the colorscale and only has an effect if marker.line.color is set to a numerical array.

Actually it seems not to be the case: http://codepen.io/anon/pen/OXJErp. Should the documentation states line.color instead?

I can do a PR to fix the doc, but I want to be sure I’m not misleading first.

[alexlenail]

Just here to note that I’d love to see this feature available in 2D.

[etpinard]

Thanks for the very detailed issue.

In plotly.js, attributes under marker.line describe the marker points’ bordering line styling (example here) and have no effect on a scatter trace’s line segments.

At the moment, scatter line attributes do not support color scales nor per-data-point style setting (as mentioned in https://github.com/plotly/plotly.js/issues/147). In other words, there is no way to apply a colour gradient to a plotly.js line chart.

Adding color scale support to line charts (possibly using svg gradient) would be a great addition to the library.