问题
I have TopoJSON file and want to add some external fields in it by id (and preserve old) without any other changes (like simplification or quantization) . So I used command like in the example in TopoJSON wiki. The command was like:
topojson -o world-110m_ext.json -e world-country-names.tsv --id-property +id -p nameENG=name world-110m.json.
But I got file smaller than the source and without any id properties. I tried to preserve id's like so:
topojson -o world-110m_ext.json -p -e world-country-names.tsv --id-property +id -p nameENG=name world-110m.json.
It did not work for me and many other ways too. What am I doing wrong?
For input I am using Mike's files from this gist.
来源：https://stackoverflow.com/questions/17450273/adding-external-properties-to-topojson-file