Can I create Line charts that automatically update over time?

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Posted by XaroRSA on 7th July 2013
Hi RGraph.

I want to make a chart that reads information from a sql database, updates automatically.
I have done this with Google Charts successfully, but google charts X-axis refuses to draw properly on new values.
Can i make a dynamic line chart using the Rgraph library, or should i stuggle on with google?


Posted by XaroRSA on 7th July 2013
Note: With the Line chart, there isn't an option to have a scale on the X axis. For this you'll need a Scatter chart with chart.line set to true. You can either use labels across the X axis or an X scale. Or now (February 2013 you could also use X axis drawing object.

Somehow, I believe google line chart has the same issue
Posted by RGraph support on 7th July 2013
Hi there,

One way is to use the setTimeout() function to set a function to happen at a future point (eg every 250ms) - and have that function then make an AJAX request to get the data from the server and then re-plot the chart with the updated data.

This chart updates dynamically with random data:

But you should be able to replace the random function with an AJAX function (eg RGraph.AJAX.getNumber() ) so that the data comes from the server instead of being random.

Richard, RGraph support

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