osp-analyze-line-or-polygon
osp-analyze-line-or-polygon [OPTIONS] INPUT-FILE
This program looks at all the ways in an OSM file and tries to classify the closed ways as linear objects or area objects depending on the tags. This is surprisingly complicated and there are several corner cases.
The program reads several expression lists from the directory specified with
--expression/-e/.
- Tags that don't tell us anything about whether an object is a linestring
or polygon (examples:
name,source, ...). We call these "neutral" tags. (There are actually three filter files read:neutral-tags,meta-tags, andimport-tags.) - Tags that tell us that the object is a linestring (examples: most
highwaytags). We call these "linestring" tags. This does not take into account that anarea=yestag could turn the object into an area. - Tags that tell us that the object is a polygon (examples: most
landusetags). We call these "polygon" tags. This does not take into account that anarea=notag could turn the object into an area.
We go through every way in the input file and, ignoring any "neutral" tags, evaluate what tags we got. Usually we can decide whether something must be a linestring or a polygon, but there are many corner cases and in some cases a decision can't be made, because none of our lists match the tags.
The result is that each way is sorted in one of the following categories:
Ways that are not closed, ie. first and last node IDs are different. These are always linestrings (or they are broken, but that doesn't concern us here).
Ways that are closed, ie. first and last node IDs are equal. These are the ways we are looking at here. The following are all subcategories of this.
This way has only "neutral" tags, so we can't decide what this is. There is at least one tag that doesn't match any of the "neutral", "linestring", and "polygon" tag lists. We can't decide what this is.
The way has an area=no tag or it has only "linestring" (and possibly
"neutral") tags.
The way has an area=yes tag or it has only "polygon" (and possibly "neutral")
tags.
The way has "linestring" and "polygon" (and possibly "neutral") tags.
The way doesn't have any tags. This is usually because it is only used in a multipolygon relation, but from the way tags alone we can't decide what they are.
The way has an area tag with a value other than yes or no. These are
definitely invalid and need to be checked and corrected.
--help, -h: Print usage information.--debug, -d: Enable debug output.--expressions, -e DIR: a directory containing filter expression files.--output, -o DIR: write output to the specified directory.
This will print out some statistics to STDOUT and create several files with
names like lp-*.osm.pbf.