Re: [OSM-talk] JOSM and scale
Lars Aronsson wrote: [some serious stuff] Also, returning to cycle lanes, the secondary road Malmslättsvägen is now marked with cycleway=lane, but this doesn't show on the map here. And how can I indicate that this bus stop is only on the southern side of the street (buses going east)? Buses going in the other direction stop at another place. Put the bus stop off the road, on the pavement. It doesn't have to be a highway node as such. Micromapping is fun. I want zoom=18 now. Hmmm... and higher GPS accuracy. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
On 26/03/2008, Mark Williams [EMAIL PROTECTED] wrote: Lars Aronsson wrote: [some serious stuff] Also, returning to cycle lanes, the secondary road Malmslättsvägen is now marked with cycleway=lane, but this doesn't show on the map here. And how can I indicate that this bus stop is only on the southern side of the street (buses going east)? Buses going in the other direction stop at another place. Put the bus stop off the road, on the pavement. It doesn't have to be a highway node as such. Its perhaps not ideal to place the bus_stop off to the side of the highway since the stop is part of the highway. Off to the side means that it is more difficult to include the feature in routing and when marking up routes on a bespoke map. However the problem of which side of the street is real and when I started adding bus_stop's in Birmingham I wondered too how I would do it. In the end I took the lead from the bus stop signage itself. Here they not only have their location (normally the name of the road they are on plus the name of a nearby cross street or major land feature) but also towards information. So I've been tagging nodes (as part of the highway) for each stop with something like this: highway=bus_stop location=Birmingham Road, Driffold towards=Sutton Coldfield route_ref=104|104A|905|905X shelter=true ref=053201 I believe the towards should work because the place names would be expected to be in the database (once the map is complete) Cheers Andy Micromapping is fun. I want zoom=18 now. Hmmm... and higher GPS accuracy. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk -- Andy Robinson ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
Andy Robinson wrote: Its perhaps not ideal to place the bus_stop off to the side of the highway since the stop is part of the highway. What's more, the bus stop is a physical area, some 5-6 metres wide that is a wedge between the street and the cycleway+sidewalk. I'd like things to be rendered like this: highway=secondary highway=cycleway highway=secondary cycleway=lane_north highway=secondary cycleway=lane_both . Ditto, with two .[bus]... bus stops ...[bus] . There is another case, that has come into fashion in the last years, where a (tertiary) street narrows so that the bus stop blocks the road in both directions: =--[bus]--=== -- Lars Aronsson ([EMAIL PROTECTED]) Aronsson Datateknik - http://aronsson.se ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Andy Robinson wrote: On 26/03/2008, Mark Williams [EMAIL PROTECTED] wrote: Lars Aronsson wrote: [some serious stuff] Also, returning to cycle lanes, the secondary road Malmslättsvägen is now marked with cycleway=lane, but this doesn't show on the map here. And how can I indicate that this bus stop is only on the southern side of the street (buses going east)? Buses going in the other direction stop at another place. Put the bus stop off the road, on the pavement. It doesn't have to be a highway node as such. Its perhaps not ideal to place the bus_stop off to the side of the highway since the stop is part of the highway. Off to the side means that it is more difficult to include the feature in routing and when marking up routes on a bespoke map. However the problem of which side of the street is real and when I started adding bus_stop's in Birmingham I wondered too how I would do it. In the end I took the lead from the bus stop signage itself. Here they not only have their location (normally the name of the road they are on plus the name of a nearby cross street or major land feature) but also towards information. So I've been tagging nodes (as part of the highway) for each stop with something like this: highway=bus_stop location=Birmingham Road, Driffold towards=Sutton Coldfield route_ref=104|104A|905|905X shelter=true ref=053201 I believe the towards should work because the place names would be expected to be in the database (once the map is complete) Cheers Andy I've avoided bus stuff round my part of the country as I don't use them nor really know how best to tackle this issue - maybe later... IMHO this ought to be covered better by relations - at present, bus routes are being written to overlie other ways (load IOW into josm run Validator to see an example), which is OK but adds yet more data, with duplication. The stops have been tagged off to one side - not by me - which looks pretty clear, and could easily be grouped into the No 63 bus relation. This ought to suit routing fine well. The current system doesn't look right to me. In your scheme you can't tell which side it is without some pretty specialist routines to calculate your 'towards' tag. How does your hypothetical routing know the bus doesn't turn right at Driffold take the scenic route to Sutton Coldfield via Clifton Road the park? (OK, the lack of bus stops, but you can't rely on that as a principle). I think bus stops are actually a pavement feature, for pedestrians, and live offset from the way. Your location tag says which road it belongs to, my offset says which way it goes which side it's on. I don't see anyone suggesting post-box is a highway feature so postmen can plan routes round them :) Neither bus companies nor the mail use a live algorithm to route themselves, so I doubt the utility of all this. Perhaps I'll work out one of my local routes try it my way see how/if it works. Mark -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Using GnuPG with Mandriva - http://enigmail.mozdev.org iD8DBQFH6olJJfMmcSPNh94RAt4mAJ45Lzzho9ZcRR77XkYonrDWIToWGgCgg2tA H0i1KoYvpRMHQzgFxdK7CoQ= =u6kA -END PGP SIGNATURE- ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
Also, returning to the scale bar issue: I was wrong, if you draw a circle in Mercator it 's more or less a circle in the real world, as long as you are in a low scale, so the scale bar in Mercator will be correct both horizontally and vertically when it s fixed- Lucas De: [EMAIL PROTECTED] en nombre de Mark Williams Enviado el: mié 26/03/2008 18:35 Para: Andy Robinson CC: talk@openstreetmap.org Asunto: Re: [OSM-talk] JOSM and scale -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Andy Robinson wrote: On 26/03/2008, Mark Williams [EMAIL PROTECTED] wrote: Lars Aronsson wrote: [some serious stuff] Also, returning to cycle lanes, the secondary road Malmslättsvägen is now marked with cycleway=lane, but this doesn't show on the map here. And how can I indicate that this bus stop is only on the southern side of the street (buses going east)? Buses going in the other direction stop at another place. Put the bus stop off the road, on the pavement. It doesn't have to be a highway node as such. Its perhaps not ideal to place the bus_stop off to the side of the highway since the stop is part of the highway. Off to the side means that it is more difficult to include the feature in routing and when marking up routes on a bespoke map. However the problem of which side of the street is real and when I started adding bus_stop's in Birmingham I wondered too how I would do it. In the end I took the lead from the bus stop signage itself. Here they not only have their location (normally the name of the road they are on plus the name of a nearby cross street or major land feature) but also towards information. So I've been tagging nodes (as part of the highway) for each stop with something like this: highway=bus_stop location=Birmingham Road, Driffold towards=Sutton Coldfield route_ref=104|104A|905|905X shelter=true ref=053201 I believe the towards should work because the place names would be expected to be in the database (once the map is complete) Cheers Andy I've avoided bus stuff round my part of the country as I don't use them nor really know how best to tackle this issue - maybe later... IMHO this ought to be covered better by relations - at present, bus routes are being written to overlie other ways (load IOW into josm run Validator to see an example), which is OK but adds yet more data, with duplication. The stops have been tagged off to one side - not by me - which looks pretty clear, and could easily be grouped into the No 63 bus relation. This ought to suit routing fine well. The current system doesn't look right to me. In your scheme you can't tell which side it is without some pretty specialist routines to calculate your 'towards' tag. How does your hypothetical routing know the bus doesn't turn right at Driffold take the scenic route to Sutton Coldfield via Clifton Road the park? (OK, the lack of bus stops, but you can't rely on that as a principle). I think bus stops are actually a pavement feature, for pedestrians, and live offset from the way. Your location tag says which road it belongs to, my offset says which way it goes which side it's on. I don't see anyone suggesting post-box is a highway feature so postmen can plan routes round them :) Neither bus companies nor the mail use a live algorithm to route themselves, so I doubt the utility of all this. Perhaps I'll work out one of my local routes try it my way see how/if it works. Mark -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Using GnuPG with Mandriva - http://enigmail.mozdev.org http://enigmail.mozdev.org/ iD8DBQFH6olJJfMmcSPNh94RAt4mAJ45Lzzho9ZcRR77XkYonrDWIToWGgCgg2tA H0i1KoYvpRMHQzgFxdK7CoQ= =u6kA -END PGP SIGNATURE- ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
El Miércoles, 26 de Marzo de 2008, Lars Aronsson escribió: The optimal solution for computerized maps is to use Mercator on the local level and a picture of a rotating globe on the world map, just like Google Earth does. But that's a lot harder to do on the web with today's technology (HTML, AJAX and a tile server). It could be done with a bit of help from HTML5's canvas element. Gotta study how those javascript rotation matrices and temporary canvases work, tough... Given that, the optimal solution would be local gnomonic projections, or UTM zones. If you use spherical mercator for rendering on a global basis, you'll hit a problem with the zoom levels. In other words, roads rendered at z17 near the equator are a lot more cramped than z17 roads in, say, Finland. -- -- Iván Sánchez Ortega [EMAIL PROTECTED] USERS ERROR. REPLACE USER AND PRESS ANY KEY. (Deep Blue. 1997) signature.asc Description: This is a digitally signed message part. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
Yes, they are probably using the same scale bar for WGS84 and Mercator. As far as I know, in WGS84, the scale bar is correct vertically (lat), but in Mercator, that scale bar is wrong both vertically and horizontally if you are far away from the Equator. As you say, one easy way would be to consider the latitude of, for example, the center of the map when calculating the length of the scale bar. Lucas De: [EMAIL PROTECTED] en nombre de Lars Aronsson Enviado el: mar 25/03/2008 12:41 Para: talk@openstreetmap.org Asunto: [OSM-talk] JOSM and scale At the equator, each degree of latitude or longitude represents a distance of 111 km. At latitude 60° (N or S), each latitude degree is still 111 km but since cos 60° = 0.5, each longitude degree is just half of that or 55.5 km. In JOSM, when I use the Mercator projection method, look at the equator and zoom out until the little scale bar in the top left corner is 111 km, the difference in longitude between the ends of this bar is one degree. That's fine. But if I look at 60° N (e.g. Stockholm) and repeat the exercise, the end points of the 111 km scale bar is still one degree. That's an error, it should be two degrees. Or rather, when the bar represents one degree, the label should say 55.5 km instead of 111 km. I've never cared too much about that scale, but now I know that these apartment buildings along Syrengatan are 11 x 32 metres and not 22 x 64 metres as JOSM would lead you to believe, http://www.openstreetmap.org/?lat=58.407lon=15.600zoom=17layers=0BFT Also, returning to cycle lanes, the secondary road Malmslättsvägen is now marked with cycleway=lane, but this doesn't show on the map here. And how can I indicate that this bus stop is only on the southern side of the street (buses going east)? Buses going in the other direction stop at another place. Micromapping is fun. I want zoom=18 now. Hmmm... and higher GPS accuracy. -- Lars Aronsson ([EMAIL PROTECTED]) Aronsson Datateknik - http://aronsson.se http://aronsson.se/ ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Juan Lucas Dominguez Rubio wrote: | Yes, they are probably using the same scale bar for WGS84 and Mercator. | | As far as I know, in WGS84, the scale bar is correct vertically (lat), | but in Mercator, that scale bar is wrong both vertically and | horizontally if you are far away from the Equator. | | As you say, one easy way would be to consider the latitude of, for | example, the center of the map when calculating the length of the scale bar. Please make the scale bar accurately measure what is under it, rather scaling it to the center of the map. I like to move the map around so that things are near the scale bar to get an approximation of how big something is. If the scale bar cannot be to within about 5% of correct for the whole screen (e.g. when zoomed out to see the whole world), I think it should be hidden, or maybe some kind of max and min scale could be shown - perhaps with another scale bar at the bottom of the screen. Thanks, Robert (Jamie) Munro -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.6 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFH6TXDz+aYVHdncI0RAtzYAJ9kTtZ3RtnH0UA4/6vLkgjG+RKnGQCfTADa djo5AQ+NV9Oj8ttKCwWCF+k= =QdHA -END PGP SIGNATURE- ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
On 25/03/2008 17:16, Andy Robinson (blackadder) wrote: Vector editing software such as CAD packages are normally scale free at the editing level. The co-ordinates are simply sufficient, especially if you have the ability to draw a vector a specific distance from a point as a polar ray or snapped relative to something else. Its only at plot time do you decide what scale you wish to make your view. Perhaps if JOSM worked the same way there would really be no need for a scale bar, especially when the scale bar needs to read differently for vertical and horizontal projection distances. I disagree. I often dictate 'postbox 10m after junction' or '... set back 30m from road' by my estimate, and I need to see what that amounts to in JOSM - though apparently I have been misled so far! Which would explain why my estimates haven't seemed to correspond to reality sometimes. In Mercator distance is constant independent of orientation, isn't it? David ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
David Earl [mailto:[EMAIL PROTECTED] wrote: Sent: 25 March 2008 5:30 PM To: Andy Robinson (blackadder) Cc: 'Frederik Ramm'; 'Lars Aronsson'; talk@openstreetmap.org Subject: Re: [OSM-talk] JOSM and scale On 25/03/2008 17:16, Andy Robinson (blackadder) wrote: Vector editing software such as CAD packages are normally scale free at the editing level. The co-ordinates are simply sufficient, especially if you have the ability to draw a vector a specific distance from a point as a polar ray or snapped relative to something else. Its only at plot time do you decide what scale you wish to make your view. Perhaps if JOSM worked the same way there would really be no need for a scale bar, especially when the scale bar needs to read differently for vertical and horizontal projection distances. I disagree. I often dictate 'postbox 10m after junction' or '... set back 30m from road' by my estimate, and I need to see what that amounts to in JOSM - though apparently I have been misled so far! Which would explain why my estimates haven't seemed to correspond to reality sometimes. That's a normal type of requirement in CAD too. You know you are 10 or 30m from another object so you use that object as the reference to draw the new object a set distance away using one of the tools. If you have those sorts of tools you find you don't need a distance/scale bar. Cheers Andy In Mercator distance is constant independent of orientation, isn't it? David ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
In Mercator distance is constant independent of orientation, isn't it? I don't know what you mean exactly. If you use JOSM with the Mercator projection and draw a perfect circle in the North of Sweden, you are actually drawing a horizontal ellipse (east-west oriented) in the real world. Lucas Juan Lucas Domínguez Rubio Prodevelop SL, Valencia (España) Tlf.: 96.351.06.12 -- Fax: 96.351.09.68 http://www.prodevelop.es http://www.prodevelop.es/ De: [EMAIL PROTECTED] en nombre de David Earl Enviado el: mar 25/03/2008 18:30 Para: Andy Robinson (blackadder) CC: talk@openstreetmap.org Asunto: Re: [OSM-talk] JOSM and scale On 25/03/2008 17:16, Andy Robinson (blackadder) wrote: Vector editing software such as CAD packages are normally scale free at the editing level. The co-ordinates are simply sufficient, especially if you have the ability to draw a vector a specific distance from a point as a polar ray or snapped relative to something else. Its only at plot time do you decide what scale you wish to make your view. Perhaps if JOSM worked the same way there would really be no need for a scale bar, especially when the scale bar needs to read differently for vertical and horizontal projection distances. I disagree. I often dictate 'postbox 10m after junction' or '... set back 30m from road' by my estimate, and I need to see what that amounts to in JOSM - though apparently I have been misled so far! Which would explain why my estimates haven't seemed to correspond to reality sometimes. In Mercator distance is constant independent of orientation, isn't it? David ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
Hi, In Mercator distance is constant independent of orientation, isn't it? No, the effect is just not as pronounced as it is if you use EPSG4326. Bye Frederik -- Frederik Ramm ## eMail [EMAIL PROTECTED] ## N49°00'09 E008°23'33 ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
On 25/03/2008 19:16, Iván Sánchez Ortega wrote: quote who=David Earl In Mercator distance is constant independent of orientation, isn't it? Wrong. Quoting Wikipedia: While the direction and shapes are accurate on a Mercator projection, it distorts the size. In other words, the Mercator projection is conformal, but not equidistant. In other words, it preserves shapes while deforming distances and areas greatly. I think that your question really is in the lines of: In Mercator, *in a small area*, the vertical scale is the same as the horizontal scale, which is the same as any diagonal scale? The answer is yes. (You'll still suffer from a very tiny deformation, something like 1/10 perhaps - the smaller the area you're working in, the smaller the deformation you'll be suffering from. And I think that's true for most map projections.) OK, I wasn't being specific enough. Yes, of course I meant at the scales that you tend to be editing at. David ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
quote who=David Earl In Mercator distance is constant independent of orientation, isn't it? Wrong. Quoting Wikipedia: While the direction and shapes are accurate on a Mercator projection, it distorts the size. In other words, the Mercator projection is conformal, but not equidistant. In other words, it preserves shapes while deforming distances and areas greatly. I think that your question really is in the lines of: In Mercator, *in a small area*, the vertical scale is the same as the horizontal scale, which is the same as any diagonal scale? The answer is yes. (You'll still suffer from a very tiny deformation, something like 1/10 perhaps - the smaller the area you're working in, the smaller the deformation you'll be suffering from. And I think that's true for most map projections.) -- Iván Sánchez Ortega [EMAIL PROTECTED] Un ordenador no es un televisor ni un microondas, es una herramienta compleja. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
Robert (Jamie) Munro wrote: Sent: 25 March 2008 10:27 PM To: Juan Lucas Dominguez Rubio Cc: talk@openstreetmap.org Subject: Re: [OSM-talk] JOSM and scale -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Juan Lucas Dominguez Rubio wrote: | In Mercator distance is constant independent of orientation, isn't it? | | I don't know what you mean exactly. | | If you use JOSM with the Mercator projection and draw a perfect circle | in the North of Sweden, you are actually drawing a horizontal ellipse | (east-west oriented) in the real world. Are you sure you are talking about the Mercator projection? AFAIK, if the circle is small, it will remain a circle. In the mercator projection, as you move away from the equator the lines move further apart. The amount of distortion will depend on how large the circle is and how far it is from the equator. Indeed, drawing in the new http://en.wikipedia.org/wiki/Large_Hadron_Collider tunnels at CERN will be interesting :-) Cheers Andy Robert (Jamie) Munro -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.6 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFH6XxCz+aYVHdncI0RAuDDAJ0fcIMrEzf2AiCo4GDdlU8hNqPgZACgsS9f RY3fyn3ViDMe+c4ETLL9z5Y= =8DFj -END PGP SIGNATURE- ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] JOSM and scale
Juan Lucas Dominguez Rubio wrote: If you use JOSM with the Mercator projection and draw a perfect circle in the North of Sweden, you are actually drawing a horizontal ellipse (east-west oriented) in the real world. Not true. The very idea of (the transversal) Mercator is that shapes such as circles are preserved, at least on the finer scales. JOSM's other mode (EPSG:4326) is a plain lat=x; lon=y and that does distort shapes, unless you're at the equator. Mercator maps longitudes to x, and then extends latitudes to a higher y so that shapes are preserved. Mercator is what the slippy map uses, so it's the natural setting to use in JOSM. Andy wrote: Vector editing software such as CAD packages are normally scale free at the editing level. JOSM is as scale free as any CAD program, of course. The only irritating bug is the number that is printed next to the little measurement scale in the upper left corner. At least when I'm using the Mercator setting, this needs to be multiplied with the cosine of the latitude (right?) to become correct. David wrote: I disagree. I often dictate 'postbox 10m after junction' or '... set back 30m from road' by my estimate, In Mercator distance is constant independent of orientation, isn't it? At the local level (high zoom) this is true, yes. If 150 horizontal pixels on screen is 150 metres east-west, then 150 vertical pixels on your screen is also 150 metres north-south. On the world or continental map, it's a different thing. Mercator makes Iceland (103,000 km², all north of 63°N) look as big as Spain (504,000 km², all south of 44°N), which we all know actually isn't true. The optimal solution for computerized maps is to use Mercator on the local level and a picture of a rotating globe on the world map, just like Google Earth does. But that's a lot harder to do on the web with today's technology (HTML, AJAX and a tile server). -- Lars Aronsson ([EMAIL PROTECTED]) Aronsson Datateknik - http://aronsson.se ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
