To achieve more flexibility as you want, you have to code a function with PL/pgSQL in PostgreSQL or with PHP/Python/Java/C# with Mapscript to define which is the base color (red, green, blue, yellow ...) and then to calculate the percent in the right RGB channel.
Cheers Mtro. Carlos Ruiz -------------------------------------------- On Mon, 6/23/14, Do Wi <[email protected]> wrote: Subject: Re: [mapserver-users] color attribute question To: "Carlos Ruiz" <[email protected]> Date: Monday, June 23, 2014, 2:56 PM thanks allot! Steve and another user here mentioned this path and it did work!only problem is that it cannot be changed later if for example the user chooses a blue gradient. how will i go about doing it with mapscript? maybe it relates to my question herehttp://gis.stackexchange.com/questions/102862/when-to-choose-mapscript-over-mapfile-or-vice-versa :-) thanks allot!dovi On Mon, Jun 23, 2014 at 6:13 PM, Carlos Ruiz <[email protected]> wrote: Do, If you want to do this without using mapscript, you can pull the gradient calculation as an attribute from your data table. ALTER TABLE mytable ADD COLUMN gradient_color VARCHAR; UPTATE mytable SET gradient_color = floor(gradient * 255)::text || ' 0 0'; Cheers Mtro. Carlos Ruiz On Monday, June 23, 2014 4:59 PM, "Lime, Steve D (MNIT)" <[email protected]> wrote: You can compute a color string using PostgreSQL string functions: SELECT percentage || ‘ 0 0’ AS color FROM … Steve From: [email protected] [mailto:[email protected]] On Behalf Of Do Wi Sent: Sunday, June 22, 2014 3:50 PM To: [email protected] Subject: [mapserver-users] color attribute question hi! i have this scenario: i have a column in my postgis table which contains a double representing a percentage. i want to color my polygons in a gradient fashion based on that number. the docs states three ways to specify color: 1. three [1-255] numbers 2. hex string 3. [attribute] but the attribute must be a string by itself in the same format as options 1 or 2. how can i achieve something like COLOR [percentage]*255 0 0 or COLOR [percentage] 0 0 if percentageis already 0..255 for a red gradient for example? thanks allot! _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users
