feature request: polar plots

[ZacDiggum]

Hi,

any chance you're going to add polar plots to pyqtgraph? Like so? I read the post about DIY polar plots in the google group.

[hudnash]

I need this as well. I've used matplotlib, but a PyQtGraph polar plot would be extremely helpful due to its real-time capabilities.

[campagnola]

It's pretty straightforward to make a polar plot manually (I think this is the post @ZacDiggum referred to): https://groups.google.com/d/msg/pyqtgraph/9Vv1kJdxE6U/FuCsSg182jUJ

But let's imagine this gets baked into pyqtgraph as a new feature. What would the API look like for showing a polar grid? How would user interaction work? Do grid lines automatically (dis)appear as you zoom in/out? Should we handle the polar transform for the user, or leave it to them?

[hudnash]

Mr. Campagnola, Thanks for the forum link. This helps a lot. If pyqtgraph were to implement this feature, they probably would incorporate a degree of flexibility equivalent to that of line graphs and scatter plots they have already provided. I prefer pyqtgraph's process for creating these graphs over more popular (but non-realtime) libraries such as matplotlib; however, in matplotlib, the type of chart can be changed by setting the "projection" attribute to "polar." This would be a great way to handle the addition of polar projections in pyqtgraph, as it is extremely straightforward and does not limit the user's ability to customize the format of the graph. Pyqtgraph is much better for realtime applications than matplotlib because it does not print images, and this is why I was curious as to whether pyqtgraph has this type of resource. I'll check out the manual method and that will most likely be just fine for me. But, to answer your question, polar charts would be simply a type of projection of graph (not a type of graph in itself). There might be two projection attributes, *linear *and *polar*, and this would allow even more flexibility within the already phenomenal pyqtgraph library. Thanks again, Hudson

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On Wed, Jul 11, 2018 at 8:24 PM, Luke Campagnola ***@***.***> wrote: It's pretty straightforward to make a polar plot manually (I think this is the post @ZacDiggum <https://github.com/ZacDiggum> referred to): https://groups.google.com/d/msg/pyqtgraph/9Vv1kJdxE6U/FuCsSg182jUJ But let's imagine this gets baked into pyqtgraph as a new feature. What would the API look like for showing a polar grid? How would user interaction work? Do grid lines automatically (dis)appear as you zoom in/out? Should we handle the polar transform for the user, or leave it to them? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#452 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AiONBOgnDYCacOuFIL9jeP0olPfkpoNJks5uFqVpgaJpZM4MMHc4> .

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[sarnold]

Any room for movement on this feature? Currently I only have time to make annoying reminders...

[j9ac9k]

to implement this feature we need to add substnatial capability in the library to address non-linear transformations. Qt does not provide us with any functionality in that regard which is why we've been hesitant to go there (also it relates to how awful our log support is).

That said, there is work happening to support non-linear transformations via the coorx library but it will be a while before that is rolled out.