I want to compare road centreline attributes to see if they have different attributes where they meet. For example, perhaps the split in road lines is because the speed limit changes. In this case I want to compare the two lines to test whether the speed limit changes at this split.

My initial idea was to use LineJoiner to merge connected lines, using the speed limit attribute to do the join. Then to create points at the start and end points for each line, and then to compare the two closest points to see if the speed limit changes. However, I am struggling in creating the points for the start/end locations and keeping the attributes.

The vertexExtractor only seems to create one point at the split locations, which does not allow the comparison to be done.

Are there better transformers to use to achieve what I am trying to do?

1 Answer 1


There are a few options you could use for this. However, I think you're on the right track with using LineJoiner (renamed LineCombiner in 2017.0). If you use the Group By function, it will only combine lines which have the same attribute or attributes you specify (e.g. speed limit, or number of lanes, etc.).

In addition, you have the ability to generate a list which will store attributes of the joined features. Note, in 2017.0, you have the ability to store selected attributes. Here I've shown "All Attributes" to be added to the list which is what you'll get in previous versions.

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You can do further analysis on your lists using the List transformers.

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