waveform chart gaps

[ThijsBoeree]

Hi,

If completed my application for data acquisition, onlyi'mnot that happywithmy waveform chart... It shows gaps, time to time? And i don't know why?

Here is an example:

Does anyone has a solution for this?

Regards,

Thijs

[Hooovahh]

The only time I've seen gaps in graphs or charts, is when you try to graph the value "NaN" (not a number).  This usually comes about by doing some math that has a result that can't be represented.  Dividing by zero is a common way of making a value NaN.  You'll need to do some debugging to figure out why your value became NaN and probably use the Not a Number check (under the comparision palette) to catch when this happens.

[ThijsBoeree]

Maybe that could be the case, i'll check for emty arrays and only write to my graph when there's data. I can only check this next tuesday... I had this once in another apication i recall. But if i write empty arrays to a waveform chart it shouldn't fill it either...? Mmmh??

Best regards,
Thijs

[ThiCop]

Hello Thijs,

Please note that NaN's are not the same as empty arrays.
It would indeed be a good idea to look at (or better to log) the data that you're currently sending to the chart.

This will give you some more insight.

If it does not help, then do not hesitate to share some sample code.

It might prove useful to pinpoint the source of your gaps.

[Hooovahh]

I didn't want to reply until I knew for sure, but writing an empty array to a waveform chart does not create gaps. Only writing a NaN does this.

[ThijsBoeree]

I couldn't imagine i write nan's to my chart? My data is realy clean and simple... But i have to check to be sure!

[ThiCop]

Hey Thijs,

Can you perhaps log the data and share the VI?
This way I can try to reproduce it.

[ThijsBoeree]

Next tuesday... I am not at work till then...

[Michael_78]

It looks to me like square edges may not be showing properly due to rendering issues. I doubt it is NaN in this case as it looks like the same data point in the y axis. I may be wrong but I will be interested to see the original data set to see if the problem can be re created.
Michael

[stephencox]

I agree with Michael78--all of your dropouts are at zero crossings on vertical lines.  It would be quite the coincidence if you were losing data for some reason at exactly those places and those places only.  It has to be a rendering issue.  Can you feed it some data that does not have vertical lines and see if the problem disappears?