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Situation, the problem: When I have a shape file, open in a layer (JOSM), copy/paste a polygon line to the .osm layer. Upload to OSM.

Then a new layer, download the data in this area, then compare to just uploaded polygon in the shape file layer, then I see that a node is on a slightly different position. Now copy/paste the abutting polygon, I do not have a validation warning, that both nodes are on the same place, and could connect(double node) them with "fix" button. Before upload. If this is not possible it give a lot of handwork by merging nodes.

It have to do with the other lat/lon coordination numbers after download from OSM.

From this shapefile, i take out a few polygons I want copy into a new layer, this layer is the layer I want to merge with osmlayer, nodes have a slightly different coordination numbers "ready to use before layer".osm

Now to the question: I want to upload this "ready to use before layer".osm to a site and get back a file "ready for osm.osm" with the right coordinates, so that after JOSM upload, there is no slightly change of the node anymore.

Then it is possible the next day to take a other set of polygons, that is directly on it's place. And can I use the fix validation button to connect these nodes. And then upload to OSM.

Is this possible?

Is there such site?

asked 02 Mar '18, 19:07

Allroads's gravatar image

accept rate: 10%


You need to provide an example pair of coordinates before and after, without that a response is just guessing (for example the differences could simply due to rounding).

Note: if you are importing data, you need to follow which will typically include a technical discussion of the data and how it best should be transformed for use in OSM.

(03 Mar '18, 10:14) SimonPoole ♦

I am fully aware of the import guidelines. That is why, I search for solutions to make a import easier and so that others with same data can work connectively.(later)

< (for example the differences could simply due to rounding).> That is exactly the point. In JOSM, new polygon (import, basedata), node, it have a number, after upload to OSM and download again it is a rounded number. Before I make a upload, I want to make this node number a rounded number, the same as I get back from a OSM download.

I need a tool to get the rounded OSM numbers correctly.

I believe when you have a node number lat/lon, and you should upload it in OSM a 1000 times, you get the same rounded number back again and again from download. Is this true?

Maybe there should be a option in JOSM, to set a layer (importdata) to a "before importlayer".osm with the right rounded numbers that never gonna change in OSM.

I was looking/asking if there is such tool. (srcipt)?

So we can make files with the best starting point.

(03 Mar '18, 12:18) Allroads

Internally in the OSM database coordinates are represented by signed 32bit integers, see for a discussion of how this works.

To round a coordinate value in a third party source so that it should pass through the API unchanged, you would need to apply the same rules (note this fraught with a number things that could go wrong depending largely on all the intermediate steps doing things the same way). So you need to either add a plugin to JOSM that does this or preprocess the shapefiles before importing them to JOSM.

permanent link

answered 03 Mar '18, 12:46

SimonPoole's gravatar image

SimonPoole ♦
accept rate: 18%

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question asked: 02 Mar '18, 19:07

question was seen: 2,175 times

last updated: 03 Mar '18, 12:46

NOTICE: is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum