Support plotting to Smith Charts

[kiranshila]

Hey everyone!

I think adding support to plot to Smith Charts would be extremely beneficial to everyone working in RF/Microwave engineering.

It basically is a modified polar plot with a Mobius transform mapping complex numbers onto a polar plane.

There are several implementations across a few plotting backends: PGFPlots has it in LaTeX, PySmithChart and Matplotlib have it in Python, it's native in MATLAB, and InspectDR has it in Julia. But none of them implement interactability as well as the leading CAD software which utilizes Smith Charts in design work.

I think Plotly is perfect for this as it can provide a true cross-platform interactive means by which to visualize complex data for radio engineers.

I am more than happy to do a PR, I just need some guidance on how to start working on what is effectively a new axis type.

[joshuaprewitt]

I agree that it would be really useful to have a smith chart, which can be used when analyzing RF waveforms.

https://cds.cern.ch/record/1417989/files/p95.pdf

[rfriedma]

I would also like to see smith charts in plotly. I use plotly successfully for displaying engineering data and it would be great to provide a consistent experience to my users for this visualization as well.

[etpinard]

Merged into #2221 - until this gets more traction.

[lstuemke]

I have implemented Smith Charts using Plotly for my own personal use. I would love to help add this feature to Plotly if possible. Here are some screenshots of what I've done.

One with increased resolution:

[kiranshila]

@lstuemke - Awesome!!! @Gloamglozer and I are working on a PR. Would you like to join? This would be an excellent addition to Plotly and you seem to have a lot of the groundwork figured out.

[lstuemke]

Yeah absolutely, I'll help out any way I can.

[jensb]

+1

I'd love to have this as well.

[samuel-schuepbach]

Were you able to add this to plotly? This feature would be extremely helpful for us as well.
Thanks

[Gloamglozer]

Luke, jensb, and Samuel, So far I've just sketched out the attributes of a smith datatype as per the core developers advice. Still waiting on their feedback Check out 'smith_api.md' in the root of the project here https://github.com/Gloamglozer/plotly.js/tree/smith If you guys are interested in being in the loop with the plot.ly guys, just send me your emails and i'll get you guys in on the email chain so you can see their thoughts.

…

-- Eric

On Wed, Apr 15, 2020 at 10:44 AM Samuel Schüpbach ***@***.***> wrote: Were you able to add this to plotly? This feature would be extremely helpful for us as well. Thanks — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#4074 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFZA25JK7JUJGIZ4L3T5523RMXB4LANCNFSM4IGEGMWA> .

-- --Eric Valentino

[lstuemke]

@Gloamglozer , I would like to help out with this but not sure the best way to send you my email. I don't really want to post it here. Suggestions?

[lstuemke]

In the meantime, if you just want to visualize your data you can always plot your mag/angle data using Plotly's Polar Charts. They won't have the Smith gridlines, but it could be a useful workaround before Smith is released.

[Gloamglozer]

I don't really have a pressing need for them right now, I just think it would be cool to include them. I'm thinking of maybe using them in a website down the road. Concerning communication, maybe we can communicate with those guys over GitHub, i know it has that KanBan function now, not sure if there's a good chat function. There was talk of a Slack channel, it would be cool to have some sort of project tracking with whatever we use. I'll try and revive the issue with them after i'm off work today. For now, here is the content of Nicholas Krutchen's email to me from a while back:

…

------------------------------------------------------------------------------------------------------------ Hi folks! (moving Jack to bcc, adding Étienne even though he's on vacation) I'm glad you're excited to contribute! This seems like a fun and challenging problem indeed! Probably the best place to start would be a call with someone on our Plotly.js team, and our tech-lead is on holiday until the 27th, so it might be best to wait until he's back to kick things off. I'm also cc'ing Alex, who has more experience than me in adding new subplot types, in case he wants to chime in. In terms of high-level guidance, I would say that you should be thinking along the lines of adding two things to the library: a subplot type and a trace type. 1. First of all a new subplot type called "smith", similar to how we have a subplot type called "polar", so this means a set of objects in the layout part of the schema to control and configure the subplot. This will be the most challenging part, as you'll also need to design and implement all of the interactions in terms of what happens when the user clicks and drags in the plot: the zooming and panning interactions etc. 2. In tandem with that, you'll need a new kind of trace called "scattersmith", similar to how we have "scatterpolar", which will draw itself onto a given smith-type subplot. This means you'll be able to have, say, 2 smith subplots in a figure, with each of them having 2 scattersmith traces on them, for a total of 4 traces i.e. 4 legend items. If you can start studying how scatterpolar traces and polar subplots interact, you'll get a sense of what's involved. We have a few different types of subplots, each of which has a scatter-like trace that targets it, and there is a lot of reuse across these components, which is both a blessing and a curse: you get a lot for free, but you need to really grok how things fit together. I would recommend that once you've had a chance to study the polar/scatterpolar pairing, you could write up a short proposal for what the schema of attributes would look like for these new objects which we could discuss on the call. I.e. once this is implemented, what would end up in this page <https://plot.ly/javascript/reference/>, similar to the scatterpolar <https://plot.ly/javascript/reference/#scatterpolar> and polar <https://plot.ly/javascript/reference/#layout-polar> sections? This is usually how we like to start major new projects: by designing the external API first (usually keeping it as similar as possible to pre-existing elements) and then seeing what can be reused and what net-new code needs writing. This API proposal usually ends up guiding the test plan, as we'll want to have tests for most or all of the API. In terms of the workflow for contributing, a good starting point is our contributing guide, <https://github.com/plotly/plotly.js/blob/master/CONTRIBUTING.md> and Mojtaba can maybe walk you through some pull requests that added new trace-types <#2954> (which we do reasonably often, we have about 40 now) and a new subplot-type <#2200> (which is quite rare, as we only have a handful) to give you a sense of what's needed here. Cheers, Nicolas

On Wed, Apr 15, 2020 at 11:23 AM Luke Stuemke ***@***.***> wrote: In the meantime, if you just want to visualize your data you can always plot your mag/angle data using Plotly's Polar Charts <https://plotly.com/javascript/polar-chart/>. They won't have the Smith gridlines, but it could be a useful workaround before Smith is released. [image: image] <https://user-images.githubusercontent.com/49922901/79354954-13b1ab00-7f0b-11ea-9aa8-19e824e4cebf.png> — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#4074 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFZA25IDF6EKHKQV5W2OEITRMXGOZANCNFSM4IGEGMWA> .

-- --Eric Valentino

[samuel-schuepbach]

We are currently using plotly plots quite extensively in our application and are planning to use some sort of smith chart feature in the near future.
So it would be perfect if we could use a plotly smith chart as well.

Keep me up to date if I can help you contributing in some way.

As for the communication, a slack channel might atually be quite useful.

Thank you for the updates.