# Web plotting when datapoints \>\> plot pixels
**URL:** https://discourse.julialang.org/t/web-plotting-when-datapoints-plot-pixels/98915
**Category:** Visualization
**Tags:** pluto, makie, plotlyjs
**Created:** [May 16, 2023, 8:11am UTC](https://discourse.julialang.org/t/web-plotting-when-datapoints-plot-pixels/98915 "2023-05-16T08:11:56Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@pepijndevos](https://discourse.julialang.org/u/pepijndevos)
#### Post date: [May 16, 2023, 8:11am UTC](https://discourse.julialang.org/t/web-plotting-when-datapoints-plot-pixels/98915/1 "2023-05-16T08:11:56Z")
Makie is pretty great for plotting big datasets, in particular the datashader functionality [datashader · Makie](https://docs.makie.org/previews/PR2883/examples/plotting_functions/datashader/)
But in the case of WGLMakie, you would first have to send the dataset to the client, which could be gigabytes.
Over in the Python world the Datashader + Holoviews + Plotly combination has a different approach: Datashader produces an image which is rendered in Plotly, and Holoviews hooks up Plotly zoom events to rerender the image. Example: [https://twitter.com/pepijndevos/status/1509948476586663937?s=19](https://twitter.com/pepijndevos/status/1509948476586663937?s=19) Docs: [Interactivity — Datashader v0.14.4](https://datashader.org/getting_started/Interactivity.html)
This way you’re only sending kilobytes of data to the client rather than gigabytes, but you can still zoom in on the data and see increased details.
I think it would definitely be possible and useful to have access to this approach for big data notebooks, but I haven’t quite figured out all the plumbing, so I thought I’d share what I got and maybe someone has better ideas.
Basically I use Makie to generate a static plot, and use `show` to turn it into a base64 encoded data URL. I then set this as an image on Plotly, and hook up the `plotly_relayout` event to send the plot bounds to Julia which I use to set the limits on the Makie plot.
But I haven’t actually managed to close the loop where Plotly updates with the new Makie plot.
Here is the notebook I’m playing around with: [JuliaHub](https://juliahub.com/ui/Notebooks/pepijn-devos2/Cedar/dashboad.jl)
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### Author:  [@sdanisch](https://discourse.julialang.org/u/sdanisch)
#### Post date: [May 16, 2023, 8:18am UTC](https://discourse.julialang.org/t/web-plotting-when-datapoints-plot-pixels/98915/2 "2023-05-16T08:18:54Z")
> But in the case of WGLMakie, you would first have to send the dataset to the client, which could be gigabytes.
That’s not true, you’ll only send the final image!
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### Author:  [@pepijndevos](https://discourse.julialang.org/u/pepijndevos)
#### Post date: [May 16, 2023, 8:57am UTC](https://discourse.julialang.org/t/web-plotting-when-datapoints-plot-pixels/98915/3 "2023-05-16T08:57:48Z")
Then… what’s WebGL about it if it actually doesn’t render anything in the client?
I was actually trying to confirm how it works but if I open the web inspector after it loads it shows nothing and if I reload the page it stops working altogether…
I’d imagine for small datasets you would want it the other way. Where pixels \>\> datapoints you’d want to actually render on the client. You’d also very much want this behavior if you’re generating a static HTML page where you want to be able to zoom into plotted data. So now I have the opposite question…
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### Author:  [@sdanisch](https://discourse.julialang.org/u/sdanisch)
#### Post date: [May 16, 2023, 9:08am UTC](https://discourse.julialang.org/t/web-plotting-when-datapoints-plot-pixels/98915/4 "2023-05-16T09:08:39Z")
Can you open an issue with an MWE for when it stops working?
> I’d imagine for small datasets you would want it the other way
I think you should wait until at least we actually publish this feature.
I’m planning to write a blogpost explaining all of this.
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### Author:  [@pepijndevos](https://discourse.julialang.org/u/pepijndevos)
#### Post date: [May 16, 2023, 11:21am UTC](https://discourse.julialang.org/t/web-plotting-when-datapoints-plot-pixels/98915/5 "2023-05-16T11:21:33Z")
ok thanks