Questions about Mapnik and Slippy and other stuff....

Hello all,

I have a project in mind and would like some guidence on how I can make it happen. I am having problems getting my brain around it.


I want to use gps data that I have collected to mark cemeteries for a genealogy project for the county I live in. I would like to generate maps of the county and use a slippy map on the website to browse and navigate around them. I would also like to be able to click on a location on a map to open other pages (maybe like an image map???) The only map that I want to deliver at this point is just one county in the state I live in. I want to be able to bring up a slippy map when a user selects a cemetery. Also, If they are zoomed out on a map I would like to place markers on the map of a cemetery that would allow them to click the marker and zoom down to the area. Man, I hope that make sense…

I think I know generally the components I need but would like some guidance.

I would need to use MAPNIK to generate all my mapping tiles. (Does the mapnik machine become the tile server?)

These tile are used by slippy to deliver the map and allow the user to browse around the map.

Now, what do you or can you use to make the map interactive?

Am I heading in the correct direction?

Warm Regards,


You can use mapnik to render the data. Use a webserver like Apache or Cherokee with OpenLayers to deliver the mapnik tiles to the browser. OpenLayers will show the rendered tiles as a slippy map in the browser. The clicky thing can be done by adding an extra layer to OpenLayers and load the clickable items as markers (like Google mashups).

I see no need for you to install mapnik, do you really need your own server?

If you use the tiles from Openstreetmap instead, and the tools for editing in openstreetmap, you will save lots of work. Just add the cementaries with potlatch, and then download them regularly with xapi

Ask more questions, if you don’t understand. I can be very cryptic. :slight_smile:

Ofcourse, emj is correct: You can add the cemeteries to OSM (if you want to share that information), install a webserver to host your website with an OL interface for which you define the basemap to be the slippy map from OSM (to show the cemeteries) and an extra layer with the clickable features with the extra information links etc.

The only problem with using the open street map tiles is that there are some problems with the data.

Let me clarify. I uploaded and drew many roads for the town I live in and the surrounding area, then other data was posted to the server. Well, there are two sets of roads that overlay each other and I am not sure what to do about it. As a basis, I downloaded all of the data for the county border and added my data to that. I figured it would do as a start. As far as adding the data to the open street map project, that is fine with me. If people think they can use it then that is great. You can see what I am talking bout by looking at this tile.

Can open layers be wedged into Joomla? I will look and read about this component.

Thanks again for your time and energy. I appreciate all that you guys do.



Can you give a permalink from the site so we can investigate.

If there are two sets of data in a certain area e.g. yours and data from some import, then I would suggest you look at which data appears to be the best, copy any missing data to the data that you choose to keep and delete the redundant data. Maybe you want to contact the author of that data first before doing the delete actually. OSM is a wiki, many hands make light work and hopefully better data every time someone edits it.

I have no idea if there is such a component. It is possible ofcourse, but might have a bit of programming needed.

Here it is: near Nashville and it really looks lke something is wrong there. Should probably be escalted on the mailinglist…

You would be surprised how many streets are named “Rustling oaks”…

Here is the link you requested.

It has been a while since I posted data. Someone was posting some data a while back from some archive or something. They asked if anyone wanted any certain counties. I asked for Humphries, Houston and Stewart couties in Tennessee. When the data was uploaded the result were two sets of tracks, their data and mine. As far as which data is better, I have no clue. My GPS uses waas (sp) and most times tells me I am within 6 to 10 feet. I use a Garmin GPS 60. Personally, I think my tracks are better, but it was my time and gas so I am biased. :wink:

If you zoom in further you will get a clear idea of the confusion. I don’t know whose tracks are whose, other than the majority of my tracks have a LOT of points. Hope that was helpful.



Ok, so the new data is the US Tiger data imported by Dave Hansen. I can assure you that any data generated is based upon real GPS measurements (like your data) is more accurate then the Tiger’s when we’re talking about the position of the roads. Tiger probably has more information about the roads.

What I suggest is that you contact Dave Hansen to discuss the situation. He probably has dealt with this situation before, so he might have a clue. I guess he will come up with two possible solutions: remove the Tiger data for your area or try to do a proper merge.

Merging means that you move and correct the Tiger data to the correct position based upon your GPS data (tracklog) and remov the redundant data. It’s no fun to do, surely, but eventually this situation needs to be dealt with.

I emailed Dave asking for his suggestions. I suppose since I am part of the problem with the redundant data I should help resolve the issue.