Matthew Bloch

To preserve the original polygon layer, you'll need to learn a bit about mapshaper's approach to working with multiple layers. See the section named "Working with layers" on this wiki...

Hi, sorry I've been slow to respond... haven't had time to work much on mapshaper recently. You may be reaching the limit of what mapshaper can do.... You can try...

Sorry for the late response... this would be a good feature to have, let me think about how to add it.

One option would be to save the file as GeoJSON instead of Shapefile. Or you could rename the truncated field, like this (CLI syntax) `mapshaper -i data.shp -rename-fields stroke-width=stroke-wid`

I'll look into this... thanks for attaching a sample dataset :)

I see what you mean... I will work on fixing this. Geometry errors like this can be hard to debug and fix, so it might take me a while.

In my experience, geometry errors like this are generally related to the limited precision of JavaScript's floating point math operations. The -clean function detects all the places where pairs of...

Mapshaper is unable to import the "crs" property from GeoJSON files. The current revision of the GeoJSON spec (https://tools.ietf.org/html/rfc7946) has removed the "crs" property, and states that GeoJSON files should...

One problem with your example above is that the `-o` command needs to go at the very end. Mapshaper runs commands in sequence from left to right. So in your...

The `from=` option assigns a CRS to the dataset, and if you don't specify a destination CRS, no coordinate calculations occur. I can see that the term `from` is misleading,...