topic Re: Tracked Variable line plot does not work with kinetic variables in FlexSim Forum

Tracked Variable line plot does not work with kinetic variables

sean_tully — Fri, 19 Dec 2025 09:25:10 GMT

I am modelling a water storage tank and am using a kinetic variable, storageVolume, to model tank volume (and net inflow). I don't set the volume directly, I'm only modifying storageVolume.rate in my scripts. If I put a Tracked Variable Table on the dashboard, I can see that the volume is correctly updated as the rate is changed, but if I put a Tracked Variable Line plot on the dashboard, it does not register any points.

As a quick hack, after I modify storageVolume.rate, I can do something like this:

storageVolume.value += 0.0001;

storageVolume.value -= 0.0001;

The above will make the plot work, whilst doing storageVolume.value = storageVolume.value will not.

This feels hacky - is there a better approach?

On a related topic, how can I generate a line plot of storageVolume.rate?

Re: Tracked Variable line plot does not work with kinetic variables

FelixMoehlmann — Fri, 19 Dec 2025 09:50:09 GMT

Install the chart components (Advanced tab in the chart properties). In the Statistics Collector that will now be accessible in the toolbox set the "Change Rule" to "Update".

To track the rate you can use a copy of the same Statistics Collector and just change the expression for the value column to use the rate property.

Re: Tracked Variable line plot does not work with kinetic variables

sean_tully — Fri, 19 Dec 2025 14:18:54 GMT

Thanks - that worked perfectly.