The best way to do this is to reproject your data to UTM for measurement and this is pretty easy to do with mapscript however that would require a trip to the server.
I have some js code that will reproject from WGS84 to UTM for this purpose. I got the code from here http://home.hiwaay.net/~taylorc/toolbox/geography/geoutm.html - it is free and open. I had to override a pmapper js function toGeoPoint(pxPoint) using the custom.js file in the config directory. This approach is a bit of a hack but it works - I would have written a proper pmapper plugin for it but I actually did it before the plugin functionality existed in pmapper (~ 3.0 I think). I also ended up hacking the display code so that it would indicate metres, kilometres or hectares as appropriate. Hope that helps Gabe -----Original Message----- From: Armin Burger [mailto:[EMAIL PROTECTED] Sent: Tuesday, 18 November 2008 11:29 PM To: Leonardo Rodriguez Silva Cc: pmapper-users@lists.sourceforge.net Subject: Re: [pmapper-users] How measure in meters? you cannot correctly measure in m when you projection is lat/lon if you do not use at least an approximation function, something like 'Distance on ellipsoid'. You could do a quire coarse calculation applying a factor in the config that converts from degrees to m, it will be ok for N-N but less accurate for E-W (unless you're close to the equator). 1 degree minute (arcminute) corresponds to 1 nautical mile (at the equator, or in N-S direction) , see http://en.wikipedia.org/wiki/Nautical_mile so you can calculate your factor from this correlation. After you set up this solution, please insert the description in the pmapper Wiki FAQ since every now and then someone comes up with a similar question. armin On Tue, Nov 18, 2008 at 1:02 AM, Leonardo Rodriguez Silva <[EMAIL PROTECTED]> wrote: > Hi: > > I am using geographical coordinates in WGS84. (Degrees, minutes and seconds) > > I want to modify the file js_config.php, to use the button of measurement, > and to measure in meters. > > Var pmMeasureUnits = {distance: " [m] ", area: " [m ²] ", factor:1}; > > > But Pmapper does not realize the measurement correctly with factor=1. > > > What is the variable "factor"?... What means this variable ?? > > > Thanks, and excuseme for my bad english¡¡¡¡¡¡¡ > -- > lerods > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's challenge > Build the coolest Linux based applications with Moblin SDK & win great prizes > Grand prize is a trip for two to an Open Source event anywhere in the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > pmapper-users mailing list > pmapper-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/pmapper-users > ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ pmapper-users mailing list pmapper-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pmapper-users ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ pmapper-users mailing list pmapper-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pmapper-users
