I am using the ‘assign class by thematic layer’ algorithm to create samples from a vector input. My vector input is a polygon shapefile. Every segment that touches a polygon in the thematic layer, no matter the amount of overlap, becomes a training sample. Is there a way to specify that a segment only becomes a training sample if a relative percent of the thematic layer polygon is within the segment?

One thought I had was to convert the thematic layer to another object level, then I could use the ‘Rel.area of’ feature to find which samples meet the area requirement. I haven’t tested this yet. I’m hoping there’s a more direct way to get there.  


  • Matthias Staengel

    Hi Lisa,

    Good question! Please have a look at the "convert thematic objects to samples" algorithm which directly converts your vector to samples. You have different parameters in this algorithm to define for example overlap requirements. This is a fairly new algorithm and will make your rule set more elegant ;).



  • Lisa Sinclair

    Just what I needed, thank you!

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