With BGS consent, I have put a thin JSON/REST Web Service Wrapper around http://www.geomag.bgs.ac.uk/gifs/gma_calc.html
My wrapper URL looks like this http://magcalc.appspot.com/?e=329000&n=123456&m=b.chad+at+host.com&id=c1&callback=fred When using this service PLEASE give a sensible escaped email address of yours as parameter m - this is for BGS logging. Parameters e and n are UK grid eastings and northings in metres and callback is the name of your JS function to call when the load has completed. id is an optional tag parameter that will be put in you JSON object as its "id" property. To call (asynchronously) from java script use something like function getMagAngle(e, n, id) { var script = document.createElement("script"); script.setAttribute("src", "http://magcalc.appspot.com/?e="; + parseInt(e) + "&n=" + parseInt(n) + "&m=your.email+at+goes.here" + "&id=" + id + "&callback=gotMA"); script.setAttribute("id", "jsonMagAngleScript"); script.setAttribute("type", "text/javascript"); document.documentElement.firstChild.appendChild(script); } The callback would look something like this. function gotMA(d) { if(d){ if(d.angle) alert(d.angle); } } Here is a typical return fred({"id":"m1","east":329000,"north":123,"angle": 2.02,"ordinal":"W","date":"July 2008"}); angle is in decimal degrees (precision 1/60) east or west of grid north, according to ordinal (which will be E or W), at east and north as supplied in the call. If you want to use Lat+Lon not East+North you will have to convert using one of the several javascript libraries available. Has any one come across a javascript or Python version of the USGS World Magnetic Model C Code? --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/Google-Maps-API?hl=en -~----------~----~----~----~------~----~------~--~---
