Graph Issue with Display

There seems to be an issue with displaying this graph data.

Timeline set for one month. Missing data for last two days.

Also, If I were to zoom in on the straight line in the middle of the graph I get real graph data.

Select area to zoom…

Data mysteriously appears

I have no idea why this happening or how to resolve it.


The graph is guessing (or interpolating). If you select ‘show missing data’ in top left, you will see the actual data points it has. The in between ones are estimated.

Hello Brian,

You’re right. However, the input is currently working and updating every 60S, but the graph is missing (not recording) data.

This is confusing me also…

24/Hr - Show Missing Data = On

24/Hr - Show missing data = Off (that’s a hell of an interpolation)

So it is the Feed that is recording the data. The Graph is just displaying the contents of that Feed.

What is the Feed update rate and what is the incoming Input data rate?

So I have a Feed that records every 10s but the Input data takes slightly longer than 10s so every 7 readings the Feed is null.

I can see this on the graph…

Looking at the CSV data

"Unix timestamp", "Tank:Top"
1571464610, 71.7
1571464620, 71.7
1571464630, 71.7
1571464640, 71.7
1571464650, null
1571464660, 71.7
1571464670, 71.7
1571464680, 71.7
1571464690, 71.7
1571464700, 71.7
1571464710, 71.7
1571464720, null
1571464730, 71.7
1571464740, 71.7
1571464750, 71.7
1571464760, 71.7
1571464770, 71.7
1571464780, 71.7
1571464790, 71.6
1571464800, null
1571464810, 71.6
1571464820, 71.6
1571464830, 71.7
1571464840, 71.6
1571464850, 71.7
1571464860, 71.6
1571464870, null


I’ve seen this before but I forget what the explanation is :grinning:.

What does the CSV data show?

The Feed update rate is 60s, the Input (incoming) data rate is 3 minutes. The 3 minute rate is not adjustable and I think that the only way to change the feet rate is to make a new feed (and lose current data). Is that right?

I could send the 3 minute data every 60s even though for those 3 minutes the data does not change.

It shows as null.

That is the issue and yes, once a feed has been created, you cannot change the update rate.

You will therefore always get gaps.

Try loading a graph with just that one Feed.


I modified the Input Data Rate (externally) so that a datum point is sent every 60s. This has fixed my problem. I now understand a bit more about Feed Rates vs Data Input Rates.

Thanks, Have a great weekend


Also, what type of feed is it? PHPFina or PHPTimeSeries, or something else? The Graph display varies as to what it does in the way of interpolation and missing data depending on the feed type as well as the sampling interval as already noted.


Hello Dave, data type is PHPFINA

OK, then I think what’s been said is correct. If you use PHPTimeSeries you might find some parts are a bit different.