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Home - General / All posts - New video: 10 Minute Tutorial - Find Similar Lines
Dimitri


6,899 post(s)
#05-Jan-22 12:54

There's a new video in the videos gallery page: 10 Minute Tutorial - Find Similar Lines

Despite the intricacy of the workflow, it all hangs together and, using previews to avoid errors, is easy to get right. The entire video was shot in a single take, with no editing.

Description: A fast paced video: we have two layers with roads in each layer. Our task is to find roads in both layers that are aligned with each other. However, the two different layers come from two different organizations so the roads are not identical and they do not have any attributes in common. We therefore cannot do a simple spatial join that assumes that the same roads which appear in both layers are exactly coincident.

We use buffers to find roads in both layers that are similar to each other, where the roads mostly follow the same paths. This workflow works for both Manifold Release 9 (https://manifold.net/index.shtml) and also the free Manifold Viewer (https://manifold.net/viewer/).

This is an ambitious video with lots of steps, that uses a variety of Manifold techniques to solve a demanding problem where there is no obvious single step solution. It uses buffers, joins, topology overlay, selection, table windows, computed fields and more. A lot of action in what is a relatively short video.

Mike Pelletier


1,966 post(s)
#05-Jan-22 16:00

Really like it when we see this kind of real world spatial gymnastics. It shows the need to work with the table and the map to fine tune what objects are selected. Of course, it would normally be done on much larger data. If that were the case, I think it would demonstrate how useful it would be to have some convenient means of zooming on the map to a particular record in the table without losing the current selection of records in the table. Perhaps a "zoom map" option when right clicking a table record.

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