Friday, 25 November 2022

Export cluster groups to shapefile

Biodiverse Version 4 allows users to export their cluster analyses using the same grouping process as is used to colour the branches.  

This can be convenient to reconstruct the clusters in a GIS or other graphics system.  

One issue is that only the cluster polygons (or points) are exported.  If you want to attached data from the clusters then you can export them to delimited text using the Table Grouped method (with the same grouping parameters) and use a database join to attach them to the shapefile.  The main reason for this is that shapefiles have a limit of 11 characters for field names, and many indices in Biodiverse exceed this (as well as sometimes containing characters other than letters, numbers and the underscore).  

Another point to be aware of is that each group (cell) is a separate polygon so use a dissolve to merge them if you want to remove the internal boundaries.


Pictures are better than words so here are some screenshots.  



An example cluster analysis, in this case with six clusters coloured.  

The export option is in the usual place.  It can also be accessed through the outputs tab.  



In this case the export is set to use six clusters to match the display, but you can choose whatever you like.  Other options include selecting by depth or by distance from the root (by length or depth).  



And here we have a plot of the clusters.  The colours differ but the clusters themselves are the same (and one can always update the colours).   



If you want to use the grouped clusters in a spatial condition then it is easier to do so directly - see more details here.  

If you just want to replicate the display then it is better to export the spatial data to an RGB geotiff and the tree to nexus with the colours embedded - see geotiff details here and the tree details here.  


   
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Shawn Laffan

25-Nov-2022


For more details about Biodiverse, see http://shawnlaffan.github.io/biodiverse/  


To see what else Biodiverse has been used for, see https://github.com/shawnlaffan/biodiverse/wiki/PublicationsList 


You can also join the Biodiverse-users mailing list at https://groups.google.com/group/Biodiverse-users or start a discussion at https://github.com/shawnlaffan/biodiverse/discussions 



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