Interpolate line graph while using fill(previous)


I am displaying some humidity values inside a time series Graph. I am using influxDB as Datasource.
While my humidity values are only updating on a change, the standard fill(linear) has some gaps at the end of the graph, because there is no new data.
If I use fill(previous) the last value will be shown until the end of the graph. This is fine!

But is there a possibility to interpolate the values, like fill(linear) does it? Here you can see the difference, left is fill(linear), right is fill(previous). I would like to have such a nice graph like on the left side, but with all the lines drawn to the end of the time.

Is this somehow possible?

Thank you very much!

I seriously doubt that you can do this, simply because of what “interpolate”
means. The “inter” part means “between”, so it will calculate fake or pseudo-
data points for you, in between two real ones.

If you do not have two real data points, interpolation cannot calculate
anything in between them.

At the end of a series, you only have the final data point. Until the next
data point comes along, interpolation has nothing to work on.


Hi Antony,
thank you for the reply.

I know what you mean, and I agree that interpolation is not working at the end of the graph. But What I would like to have, is just the look of the graph with fill(linear) and a horizontal line, pointing from the last known value, to the end of the graph.


I think the graph panel would require an additional option to say that this is
what you want. I’m sure it’s possible to implement, but the current panel
doesn’t do it. You might want to raise a feature request for this capability
at Issues · grafana/grafana · GitHub so that it might become available
in future.