Visualization for multiple line charts

[betodealmeida]

This PR adds a new viz type, line_multi. It's similar to the Deck.gl multi, in that it combines different saved charts (of lines) into a single chart. Here's an example combining two charts, one of them with a group by:

The viz works by fetching all the data for each chart in parallel (in Javascript), and passing the payload to the nvd3Vis function. Different time series are padded with null at the edges to bypass a bug in multiChart when timeseries have different ranges for x.

One thing I did in this PR was add a sectionOverrides config in visTypes.js, so that the datasource selector is not shown in this viz (I'll add it to the Deck.gl multi in a next PR, or I can do it in this one).

[mistercrunch]

Neat. I wonder if there is an easy way to align the ticks on both Y axes so they line up. Not a big deal but all those grey lines look a bit chaotic. If you Google image search “dual axis chart” you can see most tools out there align the ticks.

[betodealmeida]

[CrystalSun1992]

which version do u change?

[CrystalSun1992]

i try to add a new visualization ,echarts_funnel,but it does not display in the types on the front ,my version is 0.24.0 . T.T

[mistercrunch]

Build is failing :(
Oh also it could be nice to add an example in data/__init__.py this will automatically add test coverage in viz.py as all examples get unit tested.

[betodealmeida]

The build is failing due to conflicting numpy versions, not sure why that's happening. Will take another look, and also add an example.

[betodealmeida]

Added example:

[betodealmeida]

Will fix unit tests.

[mistercrunch]

Let's talk about what to do around filters, it may be easy to pass them as extra_filters

[codecov-io]

Codecov Report

Merging #4819 into master will increase coverage by 0.06%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #4819      +/-   ##
==========================================
+ Coverage   77.35%   77.41%   +0.06%     
==========================================
  Files          44       44              
  Lines        8677     8701      +24     
==========================================
+ Hits         6712     6736      +24     
  Misses       1965     1965

Impacted Files	Coverage Δ
superset/viz.py	81.7% <100%> (+0.18%)	⬆️
superset/cli.py	44.69% <100%> (+0.62%)	⬆️
superset/data/__init__.py	100% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ce0011e...513ef9c. Read the comment docs.

[betodealmeida]

@mistercrunch, I removed the SQL and filter controls in the last commit. I'll do a separate PR handling them properly, accounting for multiple datasources.

[mistercrunch]

Cool, please fix merge conflicts, as this looks like it's ready to be merged.

[anju-jsl]

@mistercrunch , can you please let me know when this feature will be released?
Thanks

[mistercrunch]

In 0.26.0, should be cut over the next week or two.