Re: [Talk-ca] [talk-ca] Merging ways
James Ewen wrote: So, do dig up an old thread again... is there a way to merge adjoining areas in Potlatch yet? I got a great answer from Adam Dunn on using the JOSM join ways feature. I'd like to be able to do this in Potlatch as it is annoying to have to switch to another editor just to be able to merge these adjoining nodes, and then join the two adjoining areas into a single common area. As David said, there isn't, but I'd be happy to look at adding one. Assuming that (as ever with Potlatch) we go for a 90% solution rather than covering every possible combination... am I right in thinking that you'd like something that combines two areas, with a shared sequence of nodes, into one? In other words: A-B-C-D-E-F-G-A and H-I-J-C-D-E-K-L-H become A-B-C-J-I-H-L-K-E-F-G-A (and D is deleted) cheers Richard ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
Re: [Talk-ca] [talk-ca] Merging ways
On Thu, Jul 5, 2012 at 11:28 AM, Richard Fairhurst rich...@systemed.net wrote: As David said, there isn't, but I'd be happy to look at adding one. That's like a promise of a Christmas present... now I'm all excited! Assuming that (as ever with Potlatch) we go for a 90% solution rather than covering every possible combination... am I right in thinking that you'd like something that combines two areas, with a shared sequence of nodes, into one? Yup, that sounds about right... In other words: A-B-C-D-E-F-G-A and H-I-J-C-D-E-K-L-H become A-B-C-J-I-H-L-K-E-F-G-A (and D is deleted) Ooh, muh brayn hertz! That was hard on the old noggin' but, yeah! That's exactly it. The issue with the Canvec data is that it is processed in tiles, and any way that crosses a tile boundary ends up getting chopped up. Linear ways are pretty easy to fix, just select both sections and join them. Areas are a little more work, as they end up with a common border. It usually isn't too hard to combine these sections. You simply need to cut the node at the start of the slice, and delete the common segment, and then do the same for the other segment. Then select each remaining segment and join them. Automating the process would be very nice as it takes a bit to select the right node, cut it, reselect it, make sure you are on the right section of the split way, and then delete the segment, times 2. Selecting both sections of the split area, and having the program find and remove the common border, and then join the two would be super cool! Here's a perfect example, a little pond that is split across a tile boundary... http://www.openstreetmap.org/browse/way/105928394 http://www.openstreetmap.org/browse/way/81343872 Nodes: 1219746948 (also part of ways 81343872 and 81343872) 1219746952 1219746955 1219746957 1219746959 1219746971 1219746974 1219746978 (also part of way 81343872) 1219746948 (also part of ways 81343872 and 81343872) Nodes: 1219746948 (also part of ways 105928394 and 105928394) 1219746978 (also part of way 105928394) 947636778 947636783 947636784 947636785 947636787 947636788 947636789 947636790 947636791 947636792 947636795 1219746948 (also part of ways 105928394 and 105928394) So we can see that nodes 1219746948 and 1219746978 are the two nodes that are shared on that common border. Remove the common ways between those nodes, and merge the remaining sections together. This is about as simple as it gets. There are other situations where relations are cut, or multiple segments need to be merged because the area crosses the boundary multiple times. However, all these situations get broken down into smaller tasks, where in the end, you do end up merging two sections together just as above. There may be more things to do afterwards, but just automating the merge task would be super! -- James VE6SRV ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
Re: [Talk-ca] Merging ways
So, do dig up an old thread again... is there a way to merge adjoining areas in Potlatch yet? I got a great answer from Adam Dunn on using the JOSM join ways feature. I'd like to be able to do this in Potlatch as it is annoying to have to switch to another editor just to be able to merge these adjoining nodes, and then join the two adjoining areas into a single common area. With the ability to import CanVec directly in Potlatch, having the ability to stitch areas back together right in Potlatch would be nice. I've been searching OSM help, but haven't found the answer yet. I might not be using the correct search terms though. -- James VE6SRV On Sat, Aug 20, 2011 at 11:15 PM, James Ewen ve6...@gmail.com wrote: Okay, how do I accomplish this task? I drew the outline of Wolf Lake by hand quite a while ago. I also imported the water features from CanVec as well. Now there are three ways defining the lake. One is the way that I drew by hand. The second is one imported from Canvec which is a simple outline with the tag natural:water. The other half of the lake (split across a CanVec tile boundary) is a multipolygon outer relation because there's an island in the lake. I have tried removing the ways that define the split in the tile, and join the two remaining halves. I can't do that because there's a tag conflict. I removed the tags from the natural:water side, and tried to join the remaining untagged way to the outer relation, but it does not want to stay joined together. One would think that you should be able to simply join the untagged way to the way defining the outer relation, completing the circular way. This should be the simple part, I would assume. The situation where each half of the lake is an outer relation with inner relations would make the process more complex as you would somehow have to make the inner relations on one of the outer relations move over to become inner relations to the other outer relation, while making only one of the outer relations define the whole lake. Having the CanVec data available is excellent, but stitching areas back together where they have been artificially split at a tile boundary is a bit of a bear for me. Anyone of the CanVec import experts out there have a bit of a tutorial lesson for me? Wolf Lake (Hand drawn) http://www.openstreetmap.org/browse/way/78288197 Wolf Lake (Canvec natural:water) http://www.openstreetmap.org/browse/way/81345148 Wolf Lake (Canvec outer relation) http://www.openstreetmap.org/browse/way/81400283 -- James VE6SRV ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
Re: [Talk-ca] Merging ways
No. There is no automated process in Potlatch2 that can do a so-called logical union of areas at the moment. The best way to do this right now is manually. You might want to ask the developers of Potlatch2 if they can code it up for you. - David E. Nelson - Original Message - From: James Ewen ve6...@gmail.com To: talk-ca talk-ca@openstreetmap.org Cc: Sent: Tuesday, July 3, 2012 7:21:10 PM Subject: Re: [Talk-ca] Merging ways So, do dig up an old thread again... is there a way to merge adjoining areas in Potlatch yet? I got a great answer from Adam Dunn on using the JOSM join ways feature. I'd like to be able to do this in Potlatch as it is annoying to have to switch to another editor just to be able to merge these adjoining nodes, and then join the two adjoining areas into a single common area. With the ability to import CanVec directly in Potlatch, having the ability to stitch areas back together right in Potlatch would be nice. I've been searching OSM help, but haven't found the answer yet. I might not be using the correct search terms though. -- James VE6SRV On Sat, Aug 20, 2011 at 11:15 PM, James Ewen ve6...@gmail.com wrote: Okay, how do I accomplish this task? I drew the outline of Wolf Lake by hand quite a while ago. I also imported the water features from CanVec as well. Now there are three ways defining the lake. One is the way that I drew by hand. The second is one imported from Canvec which is a simple outline with the tag natural:water. The other half of the lake (split across a CanVec tile boundary) is a multipolygon outer relation because there's an island in the lake. I have tried removing the ways that define the split in the tile, and join the two remaining halves. I can't do that because there's a tag conflict. I removed the tags from the natural:water side, and tried to join the remaining untagged way to the outer relation, but it does not want to stay joined together. One would think that you should be able to simply join the untagged way to the way defining the outer relation, completing the circular way. This should be the simple part, I would assume. The situation where each half of the lake is an outer relation with inner relations would make the process more complex as you would somehow have to make the inner relations on one of the outer relations move over to become inner relations to the other outer relation, while making only one of the outer relations define the whole lake. Having the CanVec data available is excellent, but stitching areas back together where they have been artificially split at a tile boundary is a bit of a bear for me. Anyone of the CanVec import experts out there have a bit of a tutorial lesson for me? Wolf Lake (Hand drawn) http://www.openstreetmap.org/browse/way/78288197 Wolf Lake (Canvec natural:water) http://www.openstreetmap.org/browse/way/81345148 Wolf Lake (Canvec outer relation) http://www.openstreetmap.org/browse/way/81400283 -- James VE6SRV ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
Re: [Talk-ca] Merging ways
On Tue, Jul 3, 2012 at 8:33 PM, David E. Nelson denelso...@yahoo.ca wrote: No. There is no automated process in Potlatch2 that can do a so-called logical union of areas at the moment. The best way to do this right now is manually. You might want to ask the developers of Potlatch2 if they can code it up for you. I guess that truly would be the icing on my cake that I'm eating then! -- James VE6SRV ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
Re: [Talk-ca] Merging ways
On Sun, Aug 21, 2011 at 11:41 PM, Adam Dunn dunna...@gmail.com wrote: Your data looks good, except for one thing: you tagged the way with the name, whereas the proper thing is to tag the relation with the name. The way should have no tags in this case (there may be other cases where the way would have tags even though is a member of a relation, but not in this case). Ah, yes... Changed that with Potlatch. I'm going to have to figure out how to do that in JOSM. How do you zoom out when selecting an area with the slippy map? All I can do is zoom in. I have to shut down the program to be able to select another area if it's larger than what I am looking at. That's really annoying. I've tried every combination of modifier keys I can think of. Where to split is up to you, and how large to make a multipoly is up to you, just as long as an individual way does not exceed 2000 nodes. Just to be sure you're aware: http://wiki.openstreetmap.org/wiki/Relation:multipolygon I had looked at multipolygons before, and had a rudimentary understanding... I missed the fact that you could define the outlines of the polygon with multiple segments. Thanks for the nudge. I had started importing CanVec tiles around Bonnyville, but never merged the edges as I didn't know how. I also ran into a problem with Merkaartor not being able to handle more than 5000 nodes at a time. Perhaps I can get things working with JOSM. -- James VE6SRV ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
Re: [Talk-ca] Merging ways
There's two methods to join two areas: you can delete the coincident segments and combine the two unclosed polygons (as you have tried), or you can use JOSM's join ways feature. What you are doing (the first method) should have worked, and I don't know why the two ways don't want to stay joined together. Make sure that the two ways are open, and that their coincident nodes are merged together (highlight them both and click 'm' on the keyboard for merge). Then select both ways and 'c' on keyboard for combine. You will get a tag conflict window that allows you to select which tags should apply to the final way, as well as which member of the relation should be kept or removed. In this case you will want to delete the tags on the way (since the relation will have the tags you need), and you will want to keep the member in the relation. For the second way (faster and less involved), you need to 'm'erge all coincident nodes, and make sure there aren't any nodes that are part of only one way or another (all coincident nodes have to be part of *both* ways). Since the coincident nodes in the middle of the lake will disappear when the areas are merged, you can just delete them without worrying about merging. Then select both ways and type 'shift-j' for join areas. Deal with the tag conflicts (again, you won't need tags on the way because the tags are in the relation), and you should be done. Shift-joining areas will handle two ways, a way and relation, or two relations, just as long as they are well formed (nodes are merged properly ahead of time and all of the ways are closed polygons [this won't work where ways have been split at 2000 nodes, since those ways are open polygons and josm won't know how to merge the two areas]). I demonstrate this technique in [http://www.youtube.com/watch?v=OJr_gucFGMY#t=3m45s] Also don't forget to copy over the name of the lake, since Canvec doesn't appear to have the name. Adam On Sat, Aug 20, 2011 at 10:15 PM, James Ewen ve6...@gmail.com wrote: Okay, how do I accomplish this task? I drew the outline of Wolf Lake by hand quite a while ago. I also imported the water features from CanVec as well. Now there are three ways defining the lake. One is the way that I drew by hand. The second is one imported from Canvec which is a simple outline with the tag natural:water. The other half of the lake (split across a CanVec tile boundary) is a multipolygon outer relation because there's an island in the lake. I have tried removing the ways that define the split in the tile, and join the two remaining halves. I can't do that because there's a tag conflict. I removed the tags from the natural:water side, and tried to join the remaining untagged way to the outer relation, but it does not want to stay joined together. One would think that you should be able to simply join the untagged way to the way defining the outer relation, completing the circular way. This should be the simple part, I would assume. The situation where each half of the lake is an outer relation with inner relations would make the process more complex as you would somehow have to make the inner relations on one of the outer relations move over to become inner relations to the other outer relation, while making only one of the outer relations define the whole lake. Having the CanVec data available is excellent, but stitching areas back together where they have been artificially split at a tile boundary is a bit of a bear for me. Anyone of the CanVec import experts out there have a bit of a tutorial lesson for me? Wolf Lake (Hand drawn) http://www.openstreetmap.org/browse/way/78288197 Wolf Lake (Canvec natural:water) http://www.openstreetmap.org/browse/way/81345148 Wolf Lake (Canvec outer relation) http://www.openstreetmap.org/browse/way/81400283 -- James VE6SRV ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
Re: [Talk-ca] Merging ways
On Sun, Aug 21, 2011 at 9:14 AM, Adam Dunn dunna...@gmail.com wrote: There's two methods to join two areas: you can delete the coincident segments and combine the two unclosed polygons (as you have tried), or you can use JOSM's join ways feature. What you are doing (the first method) should have worked, and I don't know why the two ways don't want to stay joined together. Not sure what was going on there, but Potlatch 2 didn't want to play nice. I watched your videos and decided to give JOSM yet another go... I've tried twice before and both times gave up in disgust with trying to figure out the arcane logic behind using JOSM. Perhaps I have learned a bit over the years using other editors, like Merkaartor, but this time I had better luck.I still hate using an editor with defined modes. There are far too many extra button presses to get it to just do what you want. Just to add a node to an existing way I have to press A, then click on the node, then hit ESC to stop adding a way. Why not just shift-click on the way like you do in Potlatch? I found where you can select having JOSM go to modeless like Potlatch but it doesn't seem to make any changes. Anyway, I think I managed to merge a few ways to create a one piece version of Wolf Lake. I don't think I've buggered anything up, but time will tell. About a week from now, if Wolf Lake disappears, we'll know why. Video tutorials like the ones you made are a great help. Trying to follow along in a written help file can be pretty tough if you have no idea what they are telling you to look for, or where to find the buttons to press. The video help was nice and easy to follow, and I was able to replicate the instructions given without having to go back and watch the video again to figure out what you had done. Thanks for the help Adam! BTW, what do you do with an entity that has over 1000 nodes? You said you don't like to make any that big. Do you just arbitrarily cut lakes or forests into bits? Should I just leave the Canvec tile boundaries in place if the lake is too big? When you zoom in, the lines show up, which isn't all that desirable. The only other way to reduce the number of data points would be to reduce the precision level of the depiction of the feature, which also is not desirable. -- James VE6SRV ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
Re: [Talk-ca] Merging ways
My involvement with OSM predates Potlatch by a couple months, so I learned to edit OSM with JOSM, and that's what feels most natural to me. I get frustrated trying to use Potlatch. The complete opposite of you :) Your data looks good, except for one thing: you tagged the way with the name, whereas the proper thing is to tag the relation with the name. The way should have no tags in this case (there may be other cases where the way would have tags even though is a member of a relation, but not in this case). For 1K, I split at approx the half-way mark. Doesn't need to be exactly half. Linear ways (highways, etc) just get split and left as two ways, whereas polygons (lakes, forests) get split and then made into a multipolygon relation. I think that having boundaries will be inevitable, especially when mapping out forests of Canada (a forest relation could extend hundreds of kilometers!). I'm currently experimenting with making Great Slave Lake a giant multipolygon, which may end up being the largest multipoly in OSM, since GSL is the 9th largest lake in the world, and I expect the 8 larger are tagged with coastline. I'm doing this to see how well the renderers deal with this case. I wouldn't suggest making multipolys so large, and they should be divided at smaller areas. Where to split is up to you, and how large to make a multipoly is up to you, just as long as an individual way does not exceed 2000 nodes. Just to be sure you're aware: http://wiki.openstreetmap.org/wiki/Relation:multipolygon Happy mapping! Adam On Sun, Aug 21, 2011 at 9:33 PM, James Ewen ve6...@gmail.com wrote: On Sun, Aug 21, 2011 at 9:14 AM, Adam Dunn dunna...@gmail.com wrote: There's two methods to join two areas: you can delete the coincident segments and combine the two unclosed polygons (as you have tried), or you can use JOSM's join ways feature. What you are doing (the first method) should have worked, and I don't know why the two ways don't want to stay joined together. Not sure what was going on there, but Potlatch 2 didn't want to play nice. I watched your videos and decided to give JOSM yet another go... I've tried twice before and both times gave up in disgust with trying to figure out the arcane logic behind using JOSM. Perhaps I have learned a bit over the years using other editors, like Merkaartor, but this time I had better luck.I still hate using an editor with defined modes. There are far too many extra button presses to get it to just do what you want. Just to add a node to an existing way I have to press A, then click on the node, then hit ESC to stop adding a way. Why not just shift-click on the way like you do in Potlatch? I found where you can select having JOSM go to modeless like Potlatch but it doesn't seem to make any changes. Anyway, I think I managed to merge a few ways to create a one piece version of Wolf Lake. I don't think I've buggered anything up, but time will tell. About a week from now, if Wolf Lake disappears, we'll know why. Video tutorials like the ones you made are a great help. Trying to follow along in a written help file can be pretty tough if you have no idea what they are telling you to look for, or where to find the buttons to press. The video help was nice and easy to follow, and I was able to replicate the instructions given without having to go back and watch the video again to figure out what you had done. Thanks for the help Adam! BTW, what do you do with an entity that has over 1000 nodes? You said you don't like to make any that big. Do you just arbitrarily cut lakes or forests into bits? Should I just leave the Canvec tile boundaries in place if the lake is too big? When you zoom in, the lines show up, which isn't all that desirable. The only other way to reduce the number of data points would be to reduce the precision level of the depiction of the feature, which also is not desirable. -- James VE6SRV ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
[Talk-ca] Merging ways
Okay, how do I accomplish this task? I drew the outline of Wolf Lake by hand quite a while ago. I also imported the water features from CanVec as well. Now there are three ways defining the lake. One is the way that I drew by hand. The second is one imported from Canvec which is a simple outline with the tag natural:water. The other half of the lake (split across a CanVec tile boundary) is a multipolygon outer relation because there's an island in the lake. I have tried removing the ways that define the split in the tile, and join the two remaining halves. I can't do that because there's a tag conflict. I removed the tags from the natural:water side, and tried to join the remaining untagged way to the outer relation, but it does not want to stay joined together. One would think that you should be able to simply join the untagged way to the way defining the outer relation, completing the circular way. This should be the simple part, I would assume. The situation where each half of the lake is an outer relation with inner relations would make the process more complex as you would somehow have to make the inner relations on one of the outer relations move over to become inner relations to the other outer relation, while making only one of the outer relations define the whole lake. Having the CanVec data available is excellent, but stitching areas back together where they have been artificially split at a tile boundary is a bit of a bear for me. Anyone of the CanVec import experts out there have a bit of a tutorial lesson for me? Wolf Lake (Hand drawn) http://www.openstreetmap.org/browse/way/78288197 Wolf Lake (Canvec natural:water) http://www.openstreetmap.org/browse/way/81345148 Wolf Lake (Canvec outer relation) http://www.openstreetmap.org/browse/way/81400283 -- James VE6SRV ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
