Implement error bars on date axis

[jonmmease]

Originally reported in plotly/plotly.py#1488

Here's an example that specifies error_x and flips between setting the xaxis.type property between 'date' and 'linear'.

CodePen: https://codepen.io/jonmmease/pen/zXrmOK

var fig = {
  "data": [
    {
      "error_x": {
        "array": [
          100000.0,
          100000.0,
          100000.0
        ],
        "type": "data",
        "visible": true
      },
      "type": "scatter",
      "x": [
        1554370371547.085,
        1554370471547.085,
        1554370571547.085
      ],
      "y": [
        6,
        10,
        2
      ]
    }
  ],
  "layout": {
    "xaxis": {
      "type": "linear"
      // "type": "date"
    }
  }
}

Plotly.newPlot('myDiv', fig, {showSendToCloud: true});

with xaxis.type: 'linear':

with xaxis.type: 'date':

[etpinard]

Looks like we never implemented error bars on date axes:

plotly.js/src/components/errorbars/calc.js

Line 37 in 0782274

var isVisible = (opts.visible && ['linear', 'log'].indexOf(axis.type) !== -1);

[Barsoomx]

still nothing? need it very much for lightcurves :(

[ibrewster]

Any updates on this? Workarounds? I just got a graph I am supposed to make that uses error bars on dates. I guess I can simply draw lines as a separate plot (if there is a way to keep it out of the legend?), but that seems kludgy...

[tomaszps]

@ibrewster I think I eventually got around this using a gantt chart style plot, FYI. I think it's a kinda odd use case. Unsure if that will work for the generic case but hope that helps.

[James-Firth]

Chiming in that this would also be useful when charting user-recorded data points, we have a lot of uncertainty about when exactly events happened and want to show error bars

[sherdim]

Do I understand correctly that when this bug is fixed, it will work in python plotly also?

[gvwilson]

yes, but I expect it will be some time before it gets to the head of our queue :-/