Re: [mapserver-users] World file creation
Thanks for the reply ... Lets ask this .. I am setting up an open source weather mapping application (php) I already know most of my target audience will not be able to install MapServer and or proj4. I have been trying to get a handle on various map projection's. decided to use 3 Grid (or flat non-projected) Mercator and Lambert Conformal Conic The first 2 was easy enough creating the needed Classes to convert Lat/Long to screen pixel X/Y Lambert has me lost ... every script I have found be it C, perl, python, or php all return me X/Y in meter's but for the life of me .. I cannot or have not found the magic formula to convert the meter's to screen X/Y I have looked at gPoint, PHPproj4, but they all go no further then meter's (or it at least seems like it) -Jeff Lake MichiganWxSystem.com WeatherMichigan.net TheWeatherCenter.net GRLevelXStuff.com On 7/4/2012 9:31, Brent Fraser wrote: Jeff, World files use projected x/y coordinates. Use the Proj4 library functions (in Mapscript) to project the upper left and lower right spherical lon/lat coordinates to x/y, then use the image size (length, width) to calculate the values for the world file (http://en.wikipedia.org/wiki/World_file) Best Regards, Brent Fraser On 7/3/2012 8:27 PM, Jeff Lake wrote: Maybe I'm not searching on the correct terms. But what is the magic formula for creating world files ?? I have a map of the US with the following projection info ullat=53.3638 ullon=-130.964 lrlat=18.2977 lrlon=-69.1058 sp1=0 sp2=39 cm=-95.5 rlat=36.5 width=640 height=480 projection=lambert now how on earth do you figure the meter per pixel?? prefer php, but guess I could convert ___ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users
Re: [mapserver-users] World file creation
Jeff, Most of us let a client-side (browser) JavaScript library like OpenLayers handle the screen - projection calculation (among a lot of other things). have a look at GeoMoose (http://www.geomoose.org) as a framework to bring together the server-side and client-side components. Best Regards, Brent Fraser On 7/5/2012 4:13 PM, Jeff Lake wrote: Thanks for the reply ... Lets ask this .. I am setting up an open source weather mapping application (php) I already know most of my target audience will not be able to install MapServer and or proj4. I have been trying to get a handle on various map projection's. decided to use 3 Grid (or flat non-projected) Mercator and Lambert Conformal Conic The first 2 was easy enough creating the needed Classes to convert Lat/Long to screen pixel X/Y Lambert has me lost ... every script I have found be it C, perl, python, or php all return me X/Y in meter's but for the life of me .. I cannot or have not found the magic formula to convert the meter's to screen X/Y I have looked at gPoint, PHPproj4, but they all go no further then meter's (or it at least seems like it) -Jeff Lake MichiganWxSystem.com WeatherMichigan.net TheWeatherCenter.net GRLevelXStuff.com On 7/4/2012 9:31, Brent Fraser wrote: Jeff, World files use projected x/y coordinates. Use the Proj4 library functions (in Mapscript) to project the upper left and lower right spherical lon/lat coordinates to x/y, then use the image size (length, width) to calculate the values for the world file (http://en.wikipedia.org/wiki/World_file) Best Regards, Brent Fraser On 7/3/2012 8:27 PM, Jeff Lake wrote: Maybe I'm not searching on the correct terms. But what is the magic formula for creating world files ?? I have a map of the US with the following projection info ullat=53.3638 ullon=-130.964 lrlat=18.2977 lrlon=-69.1058 sp1=0 sp2=39 cm=-95.5 rlat=36.5 width=640 height=480 projection=lambert now how on earth do you figure the meter per pixel?? prefer php, but guess I could convert ___ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users
Re: [mapserver-users] World file creation
Jeff, World files use projected x/y coordinates. Use the Proj4 library functions (in Mapscript) to project the upper left and lower right spherical lon/lat coordinates to x/y, then use the image size (length, width) to calculate the values for the world file (http://en.wikipedia.org/wiki/World_file) Best Regards, Brent Fraser On 7/3/2012 8:27 PM, Jeff Lake wrote: Maybe I'm not searching on the correct terms. But what is the magic formula for creating world files ?? I have a map of the US with the following projection info ullat=53.3638 ullon=-130.964 lrlat=18.2977 lrlon=-69.1058 sp1=0 sp2=39 cm=-95.5 rlat=36.5 width=640 height=480 projection=lambert now how on earth do you figure the meter per pixel?? prefer php, but guess I could convert ___ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users
[mapserver-users] World file creation
Maybe I'm not searching on the correct terms. But what is the magic formula for creating world files ?? I have a map of the US with the following projection info ullat=53.3638 ullon=-130.964 lrlat=18.2977 lrlon=-69.1058 sp1=0 sp2=39 cm=-95.5 rlat=36.5 width=640 height=480 projection=lambert now how on earth do you figure the meter per pixel?? prefer php, but guess I could convert -- -Jeff Lake MichiganWxSystem.com WeatherMichigan.net TheWeatherCenter.net GRLevelXStuff.com ___ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users
