Support for line width/color array?

[cpsievert]

If there are multiple paths in a single trace (separated by null(s)), it could be useful to have a different stroke-width for each path. This way, I could solve this issue, without having to draw a separate trace for each line.

Minimal example here -- http://codepen.io/cpsievert/pen/wMzdME

[etpinard]

@cpsievert I'm not 100% convinced this is worth implementing.

I think adding colorscale functionality to lines would make more sense.

How does R handle this?

[etpinard]

Ooops, my bad, I thought this issue was asking for line.color array support.

@cpsievert splitting trace data aroung null seems a bit magical to me. If other libraries do it, it might be enough to convince me though.

[cpsievert]

I think adding colorscale functionality to lines would make more sense.

I agree, and would be happy to open another issue for that, if you like :)

In the ggplot2 translator, we translate ggplot2 "groups" (which are sort like traces, but share visual characteristics, and don't require a legend) using this null magic since it is more efficient. I was thinking, with this array support, we could translate ggplot2 "size" in similar way (see plotly/plotly.R#340), but after thinking more carefully, it's probably better to have a traces for each group/size/color so we can have better tooltip info for the more typical use cases -- http://docs.ggplot2.org/current/geom_line.html

[etpinard]

@cpsievert keep the issue open. It's idea worth thinking about.

[etpinard]

@cpsievert looks like plotly.js could use your suggestion

7b07a25#diff-07ad6761e23a0608bb5079b46cce8951R29

The more I think about, the more I like this idea.

[cpsievert]

In addition to https://plot.ly/r/reference/#scatter-line-width accepting a data array, it'd also be useful to have https://plot.ly/r/reference/#scatter-line-color accept a data array, so I can convert a plot like this:

qplot(data = economics, x = date, y = unemploy, colour = unemploy, geom = "line")

[melvynator]

I did work on a network graph at the end of this notebook: http://nbviewer.jupyter.org/github/melvynator/DM_FinalProject/blob/master/data_exploration/.ipynb_checkpoints/data_exploration-checkpoint.ipynb
But the problem is I tried to change the size of the edge between two nodes given the value in the similarity matrix but I didn't succeed it. I think my problem and this issue are linked.

[FilipMiscevic]

I'm also trying to visualize networks and having variable line width for each edge would be desirable. Having each individual edge as a trace and setting its width independently works, but is slow in loading and not as responsive when compared to a single trace for each edge (e.g. 200 vs 1 traces). Here's an example: https://plot.ly/~fmiscevi/3/

The loading issue is so significant that the Plotly Powerpoint addin can't display these graphs... I can't be sure but it seems like it just times out while loading. I get the error "Sorry, we had to restart [the add-in] because this add-in wasn't responding."

[edward-wilson]

Adding my support for this request - I am trying to do the same thing (variable Line width) using the plotly for R package. I have multiple paths in my data, separated by NAs to build (financial candlestick data), for which I'm trying to implement dynamic widths based on the volume in that bar (processed into Low, Medium, High categories). A variable color array option would also be great. For now, I'm going to create separate traces as suggested by cpsievert, as I only have 3 different width/color categories. However, this would become an issue if you had more potential width options. Also, it's not great should I wish to change the categories.

[rreusser]

How would per-segment properties be represented? Is there precedent? Would you say:

y = [1, 2, 3, null, 5, 6]
width = [2, 2, 5, null, 1, 1]

Would the first segment get a width of 2 (the first in the segment)? 3 (the average)?

For anyone waiting on this feature, I made a quick codepen illustrating a way to fake it using fills: http://codepen.io/rsreusser/pen/zZepdO?editors=0010

To summarize, it just draws f(x) + width(x) from 0 to 1 and then walks back from 1 to 0 with f(x) - width(x) and draws it as a fill (i.e no lines).