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Question

Spatial Relate based on percent overlap

  • November 30, 2015
  • 5 replies
  • 29 views
P
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Desired functionality scenario: criteria stating the minimal Requestor overlap percentage the Supplier needs to have. (e.g., Supplier overlaps at least 80% of Requestor, or else the record is <Rejected>).

I believe that adding this property to the SpatialRelator would add a lot of value and save a lot of complexity and time.

But for now, I would like to know in as much of a step-by-step fashion as possible, how to achieve this functionality, which I believe could be accomplished more elegantly with a SpatialRelator upgrade.

Feel free to chime in if you also support this functionality.

5 replies

gio
Contributor
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  • gioContributor
  • Contributor
  • November 30, 2015

No need for tht.

You can use an AreoOnArea overlayer to test for relative overlaps.

It is not complicated to do so.

,

I don't think an upgrade is nescessary for that.

You need to use a AreOnArea overlayer.

First create a area attribute for inputstreams by ID and fme_feature_type (or create a feature_type attribute yourself). (if objects to be compared are from a transformer, you can name the transformer and then expose fme_feature_type)

Create a area attribute (for instance "original_area")

Then use AoA with a list attribute set.

After AoA you do a areacalculator named like "overlap_area".

Create a string using a stringconcatenator on the list ID.

Test on overlaps >1.

Then use a tester to test if some or more ID's are within this string (with the "IN" test).

Then calculate percentage of contributing ID's (

round(100*"overlap_area"/"original_area"))

Then test if it's 80% (or whatever precentage is required).

If it's just two different ID's things are easy.

If more then testing is more extensiv.

You can, after selection, aquire original area'by using a merger on the ID attribute. ( or rdissolve them on ID and feature_type)

V
  • vasuki
  • March 27, 2020
gio wrote:

No need for tht.

You can use an AreoOnArea overlayer to test for relative overlaps.

It is not complicated to do so.

,

I don't think an upgrade is nescessary for that.

You need to use a AreOnArea overlayer.

First create a area attribute for inputstreams by ID and fme_feature_type (or create a feature_type attribute yourself). (if objects to be compared are from a transformer, you can name the transformer and then expose fme_feature_type)

Create a area attribute (for instance "original_area")

Then use AoA with a list attribute set.

After AoA you do a areacalculator named like "overlap_area".

Create a string using a stringconcatenator on the list ID.

Test on overlaps >1.

Then use a tester to test if some or more ID's are within this string (with the "IN" test).

Then calculate percentage of contributing ID's (

round(100*"overlap_area"/"original_area"))

Then test if it's 80% (or whatever precentage is required).

If it's just two different ID's things are easy.

If more then testing is more extensiv.

You can, after selection, aquire original area'by using a merger on the ID attribute. ( or rdissolve them on ID and feature_type)

@gio Can you please elaborate on the "IN" test?

P
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  • pvaziri
  • Author
  • March 27, 2020
gio wrote:

No need for tht.

You can use an AreoOnArea overlayer to test for relative overlaps.

It is not complicated to do so.

,

I don't think an upgrade is nescessary for that.

You need to use a AreOnArea overlayer.

First create a area attribute for inputstreams by ID and fme_feature_type (or create a feature_type attribute yourself). (if objects to be compared are from a transformer, you can name the transformer and then expose fme_feature_type)

Create a area attribute (for instance "original_area")

Then use AoA with a list attribute set.

After AoA you do a areacalculator named like "overlap_area".

Create a string using a stringconcatenator on the list ID.

Test on overlaps >1.

Then use a tester to test if some or more ID's are within this string (with the "IN" test).

Then calculate percentage of contributing ID's (

round(100*"overlap_area"/"original_area"))

Then test if it's 80% (or whatever precentage is required).

If it's just two different ID's things are easy.

If more then testing is more extensiv.

You can, after selection, aquire original area'by using a merger on the ID attribute. ( or rdissolve them on ID and feature_type)

I still see a many-to-one number of steps involved rather than an optional percent-overlap parameter.

However, I'm very appreciative for you showing how to get it done!

gio
Contributor
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  • gioContributor
  • Contributor
  • March 28, 2020

@vasuki A IN (a,b,h)

search in concatenated list

gio
Contributor
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  • gioContributor
  • Contributor
  • March 28, 2020

The overlay is core, even if you put process in a tcl or python caller.

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