Hi Dane, here are the infos:
- Mapnik 0.5.1 and proj 4.6.0 - Test results: unprojected shapes, dry run 0.0262899398804 s, standard run 0.348992109299 s (that is A LOT less then the same mapfile with srs infos); projected shapes, dry run 0.0103230476379 s, standard run 0.361087083817 s. So it seems that specifying the srs in mapfile cause mapnik an unexpected overhead on calculation. If I repeat the first test, specifying the srs "+proj=latlong +datum=WGS84" for the map element and for each layer, the dry run requires quite the same time, while the standard run requires 1.66066908836 s, that is about 5 times the time requires WITHOUT the srs specification! For completeness, I'm using an Ubuntu 8.0.4 as distro. Damiano 2008/11/29 Dane Springmeyer <[EMAIL PROTECTED]> > Damiano, > > What mapnik and proj versions are you running? > > Also, what happens if you take your two comparison mapfiles and strip all > the projection information from each and then run the speed tests again? > > Mapnik will assume both mapfiles and the corresponding datasets are in WGS > 84/4326 (and of course the outputs of the google mercator will be screwy), > but it would be interesting to see if the time lag still exists. > > That would help dispel the possibility that mapnik is attempting any > reprojection. > > I also wonder whether the z-order of the reprojected shapefiles was changed > during ogr2ogr reprojection and if that might affect render speeds at all? > > Dane > > > > On Nov 29, 2008, at 12:35 AM, Damiano Morosi wrote: > > Hi all, >> >> I have the following situation: a set of shapefiles in long/lat and the >> same shapefiles reprojected using ogr2ogr, with projection "+proj=merc >> +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m >> [EMAIL PROTECTED] +no_defs". When rendering the two mapfiles (one using the >> original shapes and the other using the projected shapes), I noticed that >> the rendering time, acoording to nik2img (and tilecache, too) double. The >> nik2img tool produce quite the same output until step 35, and then in step >> 36 (rendering) the time used change. If run in dry mode with -n, the two >> maps require the same time. >> The two images produced by nik2img are 60k (original) and 74k (projected), >> but to me seems strange that a +14k image size lead to a double in rendering >> time. >> These are the mapfiles I used: >> >> ORIGINAL >> --- >> <?xml version="1.0" encoding="utf-8"?> >> <Map srs="+proj=latlong +datum=WGS84" bgcolor="#F1EEF2"> >> <Style name="My Style"> >> <Rule> >> <PolygonSymbolizer> >> <CssParameter name="fill">#f2eff9</CssParameter> >> </PolygonSymbolizer> >> <LineSymbolizer> >> <CssParameter name="stroke">#808080</CssParameter> >> <CssParameter name="stroke-width">0.1</CssParameter> >> </LineSymbolizer> >> </Rule> >> </Style> >> <Style name="Green Areas"> >> <Rule> >> <PolygonSymbolizer> >> <CssParameter name="fill">#B6FCB6</CssParameter> >> </PolygonSymbolizer> >> </Rule> >> </Style> >> <Style name="Water"> >> <Rule> >> <PolygonSymbolizer> >> <CssParameter name="fill">#B5D0D0</CssParameter> >> </PolygonSymbolizer> >> </Rule> >> </Style> >> <Style name="Major Highways"> >> <Rule> >> <MaxScaleDenominator>6000000</MaxScaleDenominator> >> <LineSymbolizer> >> <CssParameter name="stroke">#809BC0</CssParameter> >> <CssParameter name="stroke-width">.4</CssParameter> >> </LineSymbolizer> >> </Rule> >> </Style> >> <Style name="Secondary Highways"> >> <Rule> >> <MaxScaleDenominator>185000</MaxScaleDenominator> >> <LineSymbolizer> >> <CssParameter name="stroke">#EB9A9B</CssParameter> >> <CssParameter name="stroke-width">.2</CssParameter> >> </LineSymbolizer> >> </Rule> >> </Style> >> <Style name="Streets 4"> >> <Rule> >> <MaxScaleDenominator>70000</MaxScaleDenominator> >> <LineSymbolizer> >> <CssParameter name="stroke">#FDCC8B</CssParameter> >> <CssParameter name="stroke-width">.2</CssParameter> >> </LineSymbolizer> >> </Rule> >> </Style> >> <Style name="Streets 5"> >> <Rule> >> <MaxScaleDenominator>70000</MaxScaleDenominator> >> <LineSymbolizer> >> <CssParameter name="stroke">#C0C0C0</CssParameter> >> <CssParameter name="stroke-width">.2</CssParameter> >> </LineSymbolizer> >> </Rule> >> </Style> >> >> >> >> >> <Layer name="green" srs="+proj=latlong +datum=WGS84" status="1" >> clear_label_cache="0"> >> <StyleName>Green Areas</StyleName> >> <Datasource> >> <Parameter name="file">/var/www/shapes/LandUseA</Parameter> >> <Parameter name="type">shape</Parameter> >> </Datasource> >> </Layer> >> <Layer name="water" srs="+proj=latlong +datum=WGS84" status="1" >> clear_label_cache="0"> >> <StyleName>Water</StyleName> >> <Datasource> >> <Parameter name="file">/var/www/shapes/WaterPoly</Parameter> >> <Parameter name="type">shape</Parameter> >> </Datasource> >> </Layer> >> <Layer name="streets_5" srs="+proj=latlong +datum=WGS84" status="1" >> clear_label_cache="0"> >> <StyleName>Streets 5</StyleName> >> <Datasource> >> <Parameter >> name="file">/var/www/shapes/Streets5/Streets</Parameter> >> <Parameter name="type">shape</Parameter> >> </Datasource> >> </Layer> >> <Layer name="streets_4" srs="+proj=latlong +datum=WGS84" status="1" >> clear_label_cache="0"> >> <StyleName>Streets 4</StyleName> >> <Datasource> >> <Parameter >> name="file">/var/www/shapes/Streets4/Streets</Parameter> >> <Parameter name="type">shape</Parameter> >> </Datasource> >> </Layer> >> <Layer name="secHigh" srs="+proj=latlong +datum=WGS84" status="1" >> clear_label_cache="0"> >> <StyleName>Secondary Highways</StyleName> >> <Datasource> >> <Parameter name="file">/var/www/shapes/SecHwys</Parameter> >> <Parameter name="type">shape</Parameter> >> </Datasource> >> </Layer> >> <Layer name="majHigh" srs="+proj=latlong +datum=WGS84" status="1" >> clear_label_cache="0"> >> <StyleName>Major Highways</StyleName> >> <Datasource> >> <Parameter name="file">/var/www/shapes/MajHwys</Parameter> >> <Parameter name="type">shape</Parameter> >> </Datasource> >> </Layer> >> >> </Map> >> --- >> >> PROJECTED SHAPES >> --- >> <?xml version="1.0" encoding="utf-8"?> >> <Map srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 >> +y_0=0 +k=1.0 +units=m [EMAIL PROTECTED] +no_defs" bgcolor="#F1EEF2"> >> <Style name="My Style"> >> <Rule> >> <PolygonSymbolizer> >> <CssParameter name="fill">#f2eff9</CssParameter> >> </PolygonSymbolizer> >> <LineSymbolizer> >> <CssParameter name="stroke">#808080</CssParameter> >> <CssParameter name="stroke-width">0.1</CssParameter> >> </LineSymbolizer> >> </Rule> >> </Style> >> <Style name="Green Areas"> >> <Rule> >> <PolygonSymbolizer> >> <CssParameter name="fill">#B6FCB6</CssParameter> >> </PolygonSymbolizer> >> </Rule> >> </Style> >> <Style name="Water"> >> <Rule> >> <PolygonSymbolizer> >> <CssParameter name="fill">#B5D0D0</CssParameter> >> </PolygonSymbolizer> >> </Rule> >> </Style> >> <Style name="Major Highways"> >> <Rule> >> <MaxScaleDenominator>6000000</MaxScaleDenominator> >> <LineSymbolizer> >> <CssParameter name="stroke">#809BC0</CssParameter> >> <CssParameter name="stroke-width">.4</CssParameter> >> </LineSymbolizer> >> </Rule> >> </Style> >> <Style name="Secondary Highways"> >> <Rule> >> <MaxScaleDenominator>185000</MaxScaleDenominator> >> <LineSymbolizer> >> <CssParameter name="stroke">#EB9A9B</CssParameter> >> <CssParameter name="stroke-width">.2</CssParameter> >> </LineSymbolizer> >> </Rule> >> </Style> >> <Style name="Streets 4"> >> <Rule> >> <MaxScaleDenominator>70000</MaxScaleDenominator> >> <LineSymbolizer> >> <CssParameter name="stroke">#FDCC8B</CssParameter> >> <CssParameter name="stroke-width">.2</CssParameter> >> </LineSymbolizer> >> </Rule> >> </Style> >> <Style name="Streets 5"> >> <Rule> >> <MaxScaleDenominator>70000</MaxScaleDenominator> >> <LineSymbolizer> >> <CssParameter name="stroke">#C0C0C0</CssParameter> >> <CssParameter name="stroke-width">.2</CssParameter> >> </LineSymbolizer> >> </Rule> >> </Style> >> >> >> >> >> <Layer name="green" srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 >> +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m [EMAIL PROTECTED] +no_defs" >> bgcolor="#F1EEF2" status="1" clear_label_cache="0"> >> <StyleName>Green Areas</StyleName> >> <Datasource> >> <Parameter >> name="file">/var/www/shapes/proj/LandUseA</Parameter> >> <Parameter name="type">shape</Parameter> >> </Datasource> >> </Layer> >> <Layer name="water" srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 >> +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m [EMAIL PROTECTED] +no_defs" >> bgcolor="#F1EEF2" status="1" clear_label_cache="0"> >> <StyleName>Water</StyleName> >> <Datasource> >> <Parameter >> name="file">/var/www/shapes/proj/WaterPoly</Parameter> >> <Parameter name="type">shape</Parameter> >> </Datasource> >> </Layer> >> <Layer name="streets_5" srs="+proj=merc +a=6378137 +b=6378137 >> +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m [EMAIL PROTECTED] >> +no_defs" bgcolor="#F1EEF2" status="1" clear_label_cache="0"> >> <StyleName>Streets 5</StyleName> >> <Datasource> >> <Parameter >> name="file">/var/www/shapes/proj/Streets5</Parameter> >> <Parameter name="type">shape</Parameter> >> </Datasource> >> </Layer> >> <Layer name="streets_4" srs="+proj=merc +a=6378137 +b=6378137 >> +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m [EMAIL PROTECTED] >> +no_defs" bgcolor="#F1EEF2" status="1" clear_label_cache="0"> >> <StyleName>Streets 4</StyleName> >> <Datasource> >> <Parameter >> name="file">/var/www/shapes/proj/Streets4</Parameter> >> <Parameter name="type">shape</Parameter> >> </Datasource> >> </Layer> >> <Layer name="secHigh" srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 >> +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m [EMAIL PROTECTED] +no_defs" >> bgcolor="#F1EEF2" status="1" clear_label_cache="0"> >> <StyleName>Secondary Highways</StyleName> >> <Datasource> >> <Parameter name="file">/var/www/shapes/proj/SecHwys</Parameter> >> <Parameter name="type">shape</Parameter> >> </Datasource> >> </Layer> >> <Layer name="majHigh" srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 >> +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m [EMAIL PROTECTED] +no_defs" >> bgcolor="#F1EEF2" status="1" clear_label_cache="0"> >> <StyleName>Major Highways</StyleName> >> <Datasource> >> <Parameter name="file">/var/www/shapes/proj/MajHwys</Parameter> >> <Parameter name="type">shape</Parameter> >> </Datasource> >> </Layer> >> >> </Map> >> --- >> >> Thank you all, >> >> Damiano >> _______________________________________________ >> Mapnik-users mailing list >> [email protected] >> https://lists.berlios.de/mailman/listinfo/mapnik-users >> > >
_______________________________________________ Mapnik-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/mapnik-users
