I have a Torque map like this one and at the same time the bubbles are showing up I would like to render a growing graph with the number of bubbles accumulated. I don't expect CartoDB to do this for me but if CartoDB is able to send events to my JS functions I can do it.

So, the question is, is it CartoDB able to send events to JS functions when a new market is rendered?

2 Answers 2


You don't need a javascript query, you only need to know the number of bubbles per time and then get the change:time signal in torque layer.

layer.on('change:time', function(datetime) {
 // update graph

For number of bubbles you can get them from SQL API with a simple query or use this small hack I did some time ago https://gist.github.com/javisantana/622437e65cae00a7cb20


indeed Torque can send events to JS functions. maybe it's not exactly what you need (the number of bubbles accumulated) but you can set a listener on time change.

Thus you can access the time and step values. Find attached an example: http://bl.ocks.org/matallo/db7bcda00e6168a061eb

For the number of bubbles you can get them with the example query by @javisantana earlier.


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