Question

StatisticsCalculator "looses" feature?

  • 17 March 2022
  • 4 replies
  • 3 views

Hi,

 

I have the StatisticsCalculator that mysteriously looses one feature:

fme-feature-disappearedI would expect both input and output feature count would be the same.

 

The StatisticsCalculator doesn't do any group by:

 

fme-feature-disappeared2What am I not understanding?

Thanks in advance!


4 replies

Userlevel 4
Badge +26

:O - oh wow missing features is something I haven't seen in a long time. Which build of FME is this? Can you try a newer version?

 

Alternatively if running a new version of FME try upgrading the transformer to a newer version (right click - upgrade). Warning though if doing this that it might change things like attribute names so you need to be careful

:O - oh wow missing features is something I haven't seen in a long time. Which build of FME is this? Can you try a newer version?

 

Alternatively if running a new version of FME try upgrading the transformer to a newer version (right click - upgrade). Warning though if doing this that it might change things like attribute names so you need to be careful

Thanks for the reply!

 

We've got 2020.0.3.0.

 

Unfortunately, the client seems not to be willing to upgrade right now... We're soon going into production and we're performing last tests with real data.

 

The strange thing is that it happens always, just with a particular gpkg.

I'll see if I can stir the input data somehow. I understand that the behavior is not the expected.

 

Thanks!

Userlevel 4
Badge +25

It looks like the latest version anyway, given the transformer interface. What I'd do is add some checks before the transformer.

 

  • check for aggregate features. Use an AggregateFilter going into the transformer.
  • check for features without the attribute being processed
    • Use a Tester and test attribute "has a value"
  • check for features with a non-numeric value
    • Use a Tester and test attribute "type is" "numeric"

 

Basically I think there must be something odd about one feature and this will help us to find out what it is.

Hi Mark,

 

I just couldn't figure it out. All features seemed pretty same to me, all attributes similarly valued...

 

The Statistics Calculator was actually inside a custom generic transformer that just counted features and I was loosing 1 feature of 3 of a particular type (no geometry involved).

 

Finally after some tweaking, I saw that if I take the custom transformer out, it also does loose the feature in another transformer... And when I took that one out, the feature was lost in another... Seemed almost random. Finally I got rid of everything non-essential and implemented it in a more simpler way.

Luckily, it works now, but I'm still wondering what was the cause. I guess I'll never know, but might be related with the data.

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