API to get current plot area width & height

plotly.js
1

Hi,
I was wandering if there’s a way to retrieve the current plot area width/height programmatically.

My use case is: I need to display a scatter plot by querying a hufge data set on a server, like “give me all the data between 1st jan 2015 and 1st jan 2016”. This data is stored at a very high “density”, say 1 value per minute. This means that the query mentioned before would yield a HUGE amount of points (circa 550.000), which I do not want, because my chart width is, say, 1000 pixel, so to maintain readability I need the server to SAMPLE the original data and give me, say, a point for each 5 pixels (this means 200 points form the original 500.000+ )

Long story short I need to be able to know the actual plot area width so that i can compute the number of points which can fit on the screen, and query the server accordingly.

The only way I can think of is inspecting the DOM and retrieving the svg plot area width, but I’d prefer something less “hacky”

Thanks!

1 Like
2

The best way to do this at the moment would be to keep a reference to the plotly layout object you are sending to Plotly.plot.

For example:

var data = [/* some data */];
var layout = {/* some layout */};

Plotly.plot('graph', data, layout);

// then elsewhere in your code

layout.width; // => will have the up-to-date plot width
layout.height; // => will have the up-to-date plot height

I hope this helps.

3

This seems to get the height of the entire chart, including the modebar and whitespace around the chart.

Is there a way to get the height of JUST the visual plot area?

1 Like
4

Subtracting the margins should work, I think

1 Like
5

I’m looking at doing something similar, and yes - subtracting the margins is one way.

My problem at the moment is I have a colorbar. I know the mergins, the padding, and the colorbar width, but as far as I can tell the colorbar labels take up a undeterminable amount of space?

1 Like