portpocket.blogg.se - Filling shapes geometry

#FILLING SHAPES GEOMETRY UPDATE#

The formula is right at the end of the picture. On the picture above I'm creating a new one called "ID".

#FILLING SHAPES GEOMETRY UPDATE#

There, you will be given the option to create a new field or update an existing one. Probably someone already figured this, but I'll take my chances:ġ) Create an ID on the original, damaged layerĬreating an ID attribute is simple, but so is my solution, so I'll go over it.įirst, you have to open your attribute table and then go to the Field Calculator, which is a button pretty much like an abacus. So, I came up with a solution of my own which is not 100%Īutomated, but it's manageable. I've seen some explanations following the same path as gtapko and tshiffle's, but none worked for me because the invalid geometries made the difference tool disfunctional. The final result does not have any gaps.Finally, use the "Eliminate sliver polygons" tool, with the settings shown in the image.

Sort your table using an area field and take the value from the smallest polygon in the original file.

All the gaps will now appear as empty records in the database (for the example 72 rows).

Use the SAGA tool, because default QGIS option creates duplicates into the database.

Perform a Union between the initial data and the single parts.

Now you have, in a new shapefile, several polygons covering the gaps of your original coverage. For that, you could use Vector/Geometry Tools/Multipart to singleparts tool.Īfter that, delete the external entity. This action will create a new shapefile consisting in only one polygon, so you have to explode it into single parts.

First, perform the difference between your file and a polygon covering its whole extent.

In order to solve the problem, You could use a slight modification of tshiffle's method:

I faced the same problem as yours with this shapefile, having many gaps between polygons.