Charts, curves...

[skiv71]

hi, is it possible to offer an interpolated curve instead..?

just some temperature changes give a very staircase like view..

thanks

Neil

[craig]

what are the logging settings for the datapoint? If you were logging every value or onchange with a threshold of 1 this surely would not happen.

[skiv71]

the data source is updated every 5 secs, and i'm logging every 15 secs and i've set to average....

just other scada packages i've seen have the option to show an interpolated view... wondered if this could be implemented.

thanks

Neil

[craig]

you are logging the average of 3 samples every 15s and the data has steps? How fast is the temperature changing and what is the scale on the Y axis?

A screenshot may help illustrate the issue.

[skiv71]

i've snapped a screenshot...

let me know what you think

Attachment: download link

[craig]

the range on the y axis 0.6 degrees celcius. The smallest change I see plotted looks to be .02 of a degree, but the data in the data table only has 1 decimal place so the .02 probably came about as an average of 3 other numbers.

If you need the chart to be less step like with a scale of less than a degree you need a higher resolution temperature sensor.

I'm not sure what you would like the chart to look like though, I haven't seen many scada packages so I probably don't know what I'm missing!

[mlohbihler]

In ImageChartUtils at line 92 i did this:

            XYSplineRenderer numericRenderer = new XYSplineRenderer();
            //XYLineAndShapeRenderer numericRenderer = new XYLineAndShapeRenderer(true, false);

... and got a nice smooth curve. A switch for something like this could be added somewhere i suppose. I suspect you would want to use it sparingly though, since it is certainly far more processor intensive that a straight-line chart.

[skiv71]

thanks for that input... i guessed there would be a performance hit involved... maybe if the toggle was just on the fly for that viewing session and defaulted after leaving the view