Chart Node Auto-Scaling

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1

By default the chart will auto-scale on the Y axis.

Or I can specify axes values with

msg.ui_control = { "ymax": (scale_max), "ymin": (scale_min), "stepSize": '0.5' };

I'm trying to prevent a chart Y axis being too 'short'. Ideally there would be a 'minimum range' value for the Y axis, but absent being able to set that I need to ensure that ymax less ymin is not less than say, 10.

I have a function node to do this, but I'd like to be able to revert. to auto-scaling with the logic

If maximum_value - minimum_value < 10
Set axis values with function node
Else
Set axis values to auto-scale

So how do I return a chart to auto-scale the Y axis after using 'msg.ui_control', please?

2

Am I correct in understanding that if I use

msg.ui_control = { "suggestedMax": scale_max, "suggestedMin": scale_min };

That this will allow auto-scaling to continue to function?

3

I can't get this to work!

Chart of 24 hour temperature ...

image
image1396Ă—768 46.4 KB

I am sending
msg.ui_control = {"suggestedMax":scale_max,"suggestedMin":scale_min};

where scale_max = 7 and scale_min = 2

But the chart is auto-scaling from 0 to 6.

I thought that scale minimum would be "Math.min(dataMin, suggestedMin)" and that scale maximum would be "Math.max(dataMax, suggestedMax)" but clearly I'm missing something about how this is supposed to work.

4

With function node:

msg.ui_control = {
    options:{
        scales: {
            yAxes: [
                {
                ticks: {
                        suggestedMin: 50,
                        suggestedMax: 100
                    }
                }
            ]                
        }
    }
};

delete msg.payload;
return msg;
5

I was searching Github to try to find that. Many thanks.