Or a way to alter the interpretation of angles, e.g. ANGLEMODE or something like that...
Steve >>> On 8/19/2008 at 3:06 AM, in message <[EMAIL PROTECTED]>, Havard Tveite <[EMAIL PROTECTED]> wrote: > I don't think ANGLE can be used in your case (if you do not > use scripting to calculate the ANGLEs yourself for each > generated map). > > Is there a need for a new TAG - for instance with the name > "ORIENTATION", that could be used to specify compass > directions (0=north, 90=east, 180=south, 270=west) for > point symbols? > > HÃ¥vard Tveite > > John Maurer wrote: >> Thanks for the suggestion, Daniel! I was unaware of the ANGLE parameter >> in MapServer 5.0. One remaining concern I have, though, is how the angle >> will be interpreted by MapServer? Will -90 degrees always point to the >> South Pole regardless of the map projection I'm using (e.g. a polar >> stereo map centered on the South Pole), or will it always just point to >> the bottom of the map image regardless of the projection? i.e. Does >> MapServer interpret the degrees spatially or just in terms of the image? >> Unfortunately, if the latter is the case (which I suspect it probably >> is) it will not solve my problem. Do you know? Thanks again! >> Cheers, >> John Maurer >> >> Daniel Morissette wrote: >>> John Maurer wrote: >>>> Dear MapServer Users, >>>> Does anybody have experience displaying vectors in MapServer? By >>>> "vectors", I don't mean the usual vector vs. raster difference. What >>>> I mean is displaying data like wind vectors, which are point >>>> locations that have both a direction (degrees) and magnitude (e.g. >>>> meters per second). Usually these are displayed as arrows, which each >>>> point in a certain direction and whose tails vary in length depending >>>> on the magnitude each measurement. Is this possible in MapServer? >>>> Thanks for any suggestions! >>> You could bind the symbol size and angle to an attribute in your layer >>> definition. >>> >>> If you can precompute the size in pixels based on the wind speed and >>> store that to an 'arrowsize' attribute then you could use a layer >>> defn's like this: >>> >>> LAYER >>> TYPE POINT >>> ... >>> CLASS >>> SYMBOL 'arrow' >>> ANGLE [direction] >>> SIZE [arrowsize] >>> COLOR 0 0 0 >>> END >>> END >>> >>> >>> If you can't precompute the arrow size in pixels, then you could use >>> classes based on the wind speed attribute: >>> >>> LAYER >>> TYPE POINT >>> ... >>> CLASSITEM 'windspeed' >>> CLASS >>> EXPRESSION ([windspeed] < 5) >>> SYMBOL 'arrow' >>> ANGLE [direction] >>> SIZE 10 >>> COLOR 0 0 0 >>> END >>> CLASS >>> EXPRESSION ([windspeed] < 25) >>> SYMBOL 'arrow' >>> ANGLE [direction] >>> SIZE 15 >>> COLOR 0 0 0 >>> END >>> CLASS >>> EXPRESSION ([windspeed] < 100) >>> SYMBOL 'arrow' >>> ANGLE [direction] >>> SIZE 20 >>> COLOR 0 0 0 >>> END >>> CLASS >>> # No expression ... catch all for windspeed > 100 >>> SYMBOL 'arrow' >>> ANGLE [direction] >>> SIZE 25 >>> COLOR 0 0 0 >>> END >>> END >>> >>> >>> Daniel >> >> -- >> John Maurer >> Web/Database Applications Engineer >> National Snow and Ice Data Center (NSIDC) >> University of Colorado at Boulder >> http://cires.colorado.edu/~maurerj >> +1-303-586-1677 >> ------------------------------------ >> "Without geography, you're nowhere!" >> >> >> _______________________________________________ >> mapserver-users mailing list >> mapserver-users@lists.osgeo.org >> http://lists.osgeo.org/mailman/listinfo/mapserver-users >> _______________________________________________ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users