Adding multiple signals that have missing values

[dkuecker]

I need to add four signals that have missing data.  SEEQ is giving a "There is no data in your current display range" warning and not displaying the sum of the series.  Is there a way to add the existing values and ignore missing or invalid values?

[Ben Johnson]

I think you're on to something with the other topic about replacing gaps with zeros. If you applied that formula to each of these 4 gappy signals, then $a+$b+$c+$d should give you the signal you're looking for.

As background, the gaps are considered "invalid" and doing any math with an invalid value is going to result in an invalid. The gaps in each signal become viral and wipe out the others when added together.

[Guest Jon Peterson]

I'm not sure if splicing in zeros is correct. Zero is just an arbitrary value, why not -100 or +200? But, @dkuecker, let us know if a replacement fits your need. Replacement is easy to do.

Technically, if we need to add say 4 signals, we could only do the math when the there's valid data for a 4 signals--and Seeq does support that. Implying no data is a value of zero is not correct. But, as mentioned, Seeq supports splicing in other data where data is missing. 

[Adam Georgeson]

If the gaps are considered "invalid", could you write $a.validValues()+$b.validValues()+$c.validValues()+$d.validValues() ?  

[Ben Johnson]

It's not just valid samples that are the problem, it's the gaps between samples that are longer than the "maximum interpolation" of the signal. validValues() doesn't change that. Setting a long maxInterpolation on the signal probably doesn't do what you want either, since then line between the first and last sample of the gap would now interpolate and contribute to the sum of the signals.