On Fri, Sep 3, 2010 at 11:12, Chris Jackson <webturt...@gmail.com> wrote: > Hi Jukka > > Thanks for the response and the great investigative work! > My log entry for drawing the layer is - [Fri Sep 03 10:01:25 2010].658000 > msDrawMap(): Layer 1 (meanspringpeakflow), 24.500s. :o( > > I do wonder if my Mapfile layer definition is just v.poor (admittedly no > expert!) so have taken an excerpt of the layer defintion (there are about 15 > classes in all) - views anyone, should I be loading it a different way? > > Also Jukka, could I get a sample of your scale dependent WMS GROUP layer map > code - as it sounds like a great idea maybe for this but also some v.hi-res > model grids I am thinking about. > > Thanks again, much appreciated! > Chris > > LAYER > NAME "meanspringpeakflow" > TYPE polygon > DEBUG 5 > DATA "Tide" > TEMPLATE void > PROJECTION > "+proj=utm +zone=31 +ellps=GRS80 +units=m +no_defs" > END > METADATA > "DESCRIPTION" "Mean Spring Peak Flow" > "RESULT_FIELDS" "ID,DISTANCE,DEPTH,MEAN_SP_PC" > "RESULT_HEADERS" "ID,Minimum Distance (m),Average Depth (m),Mean Spring > Peak Flow (m/s)" > "ows_title" "meanspringpeakflow" > "RESULT_HYPERLINK" "ID|| Load graphing tool" > END # Metadata > CLASS > NAME '> 4.00 (m/s) ' > EXPRESSION ([MEAN_SP_PC] >= 4 AND [MEAN_SP_PC] < 4.5) > STYLE > COLOR 135 99 64 > END #end style > END # end class > CLASS > NAME '3.51 - 4.00' > EXPRESSION ([MEAN_SP_PC] >= 3.5 AND [MEAN_SP_PC] < 4) > STYLE > > COLOR 158 126 63 > END #end style > END # end class > etc etc >
you can speed things up a little by simplifying your expressions in case mean_sp_pc is a continous value: class expression ([item]>=4) ... end class expression ([item]>=3.5) #this suffices and implies [item] <4 as all entries with [item]>=4 wil have been treated by the first class ... end class ...etc... end regards, thomas > > On 3 September 2010 09:04, Rahkonen Jukka <jukka.rahko...@mmmtike.fi> wrote: >> >> Hi, >> >> I took some numbers to compare with. >> >> Material and methods >> >> Polygon layer, rather simple polygons with few vertises, Feature Count: >> 117383 >> DEBUG 5 in mapfile >> WMS client asks for the whole layer >> Mapserver 5.2.1 (CGI) on not so fast Windows computer >> Results >> First request: rendering time taken from the log file are between 3.5 and >> 4.5 seconds >> Following request, BBOX is changing but all the polygons are drawn >> though: rendering times 1.5 - 2.5 seconds >> >> Conclusions and discussion >> At first one might think that my server is faster. But this test is not >> controlled at all because we are not using the same shapefiles and we can't >> say so. What we can say that a couple of hundred of thousand polygons can be >> drawn faster. >> >> However, it does not really make sense to render an image this way if it >> should be fast. If the screen has 1000 by 1000 pixels it makes a million >> pixels together. For 200000 polygons it makes 5 pixels per polygon. You >> can simplify your polygon geometries pretty much before anybody can see the >> differense. If the polygons are spread evenly nobody can even see the >> difference if there are 20000 or 200000 polygons on the screen. >> >> We have one polygon layer with about million polygons and for that I made >> two simplified layers which contain only 1 percent and 10 percent of all the >> polygons. Those and the original shapefile are put into the same scale >> dependent WMS GROUP layer. This group is pretty fast at any scale. The 1 >> percent layer is perhaps a bit too sparse but I have been too lazy to have a >> try with 2 or 5 percent samples. >> >> -Jukka Rahkonen- > > _______________________________________________ > 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