Gps/php/maps

buducom

Is there anyone selling or offering a GPS
api which generates maps through PHP or web, XML etc?

I want to built an application where i can fix points on maps and reconstructed from the database in a fly again.

Additionally it would be very cool to receive GPS infos on mobile phones and the map the phones location.
Is that possibe?

AstroTeg

A year or two ago I had looked into doing something like this. There's an open source GIS server out there (forgot the name, but its written in C and runs in its own little world). It was kind of cool, but required a lot of processing power if you wanted a map to come back pretty quickly for just one user. Other times it would just bomb out and crash.

I had found someone in Finland (I think) wrote something in PHP to read in a particular GIS file type and build a map from it. It was meant for Europe because it wasn't handling the lat/long coordinates of North America (in theory, some tweaking would probably make it work).

Basically, I haven't found much out there. Google search and you will find bits and pieces and maybe one of those pieces will do what you need...

onion2k

Theres a GIS package in PEAR.

marque

Ploting data on a map is a little difficult to get your head around but once you figure out the maths it's quite easy.

You need ot calculate the scale of the map and the starting X and Y (x0 y0) pixcel cordinates relative to the longitude and latitude.

To do this you need to take two points of reference the further away from each other the better. Mark their X and Y cordinates in relation to the longitude and latitude and you will get the scale (pixcel:degree) with that you can get the x0 and y0 positions and use that as your final reference.

From there it's just a matter of putting a dot on a map. I've done this with flash before, only because I needed it to be updated every 10 seconds or so. But it can be done in PHP with a little GD.

AstroTeg

Originally posted by onion2k
Theres a GIS package in PEAR.

I've tried this package a year or so ago. This is the one that didnt' handle the negative longitudes. The new version says its supposed to. But I haven't been able to get it to plot any data for anything in North America (been playing with it off and on this morning). Maybe someone here can get it to work (if you do, please contact me - I'm curious to find out what you did).

AstroTeg

Ah! I figured it out:

(Northeast Ohio / Cleveland)

Tricky little bugger to figure out.