Re: [UMN_MAPSERVER-USERS] map performance

[boice tomlin]

Hi Steve,











thanks,

boice



On Dec 5, 2006, at 6:32 PM, Steve Lime wrote:

Assuming I was using static class items. Do you think my method of using a regular expression to specify which geographies to display is a good method? Thanks for the tip on saving the map file. Very cool. It looks as I expected or at least hoped. Basically my original map file with a few extra classes and regular expressions for the layers I display. Someone else suggested a method using postgis that would pull in shape data with less polygons for certain extents. Couldn't I use a version of the shape files I have now with less detail/polygons when rendering a map at larger extents? I actually want to explore every method I can for optimization. My goal is a fairly descriptive national view in 1 tenth of a second. Is that too lofty?

Might be interesting to see what the resulting mapfile (after your
dynamic work) looks like (use $map->save(...)).

We'd really need to know more about the data, how you're doing
classifications and such to comment more. There may be lots of ways
to make things go faster. From the looks of it for each geography

indicate

example state level data):

State  Hydrography  Watersheds ...
MN     0                    1
WI      3                    2
IA       3                    0
FL       1                    3

Where 0 means no responce, 1 complete and so on. So in that case your
class definitions would always be the same you'd

you wouldn't need dynamic classes (or even MapScript for that
matter).  Just thinking out loud...

Steve

(city, county, tribe, state, nation) you have a bunch of variables that if a data theme is available. One could organize that data like so (for be simply changing the variable you're mapping on (e.g. CLASSITEM), and

boice tomlin <[EMAIL PROTECTED]> 12/4/2006 1:24:58 PM >>>

Hello users,

The map located here;

http://gisinventory.net/status_maps.html

takes a while to load.  At least at the national view where there is a
lot of area to render.

I am looking for alternative ways to generate the map that will
significantly improve performance.


mapserver takes several seconds to generate it.


anyone had comments on any of them.


depend on the map files.
2) using a db such as postgres with postgis so that layer information
is available all in one compact source.

Right now I have to generate a bunch of dynamic classes in PHP using
the general method below.

$lyr = $this->ramona_map->getLayerByName("state_yes");
                $cla = $lyr->getClass(0);
                $cla->setExpression("/".$expression."/");
                $lyr->set("status", MS_ON);

I have to do this several hundred times to represent all of the data.
The time it takes to generate the map seem proportionate to the amount
of layers I make visible.  And again this is on the mapserver side and
not PHP.  PHP does its part of the operation in thousandths of a
second.

anyone's thoughts are greatly appreciated.

-boice tomlin



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boice tomlin


[EMAIL PROTECTED]


503-528-6204

Currently I am using php and looping through data and turning on layers as I go. The PHP part is lightning fast. But after I get the map ready I'm curious about alternative ways to handle this problem and wonder if 1) modifying the shape files in some way so the layer information is in those files so that all mapserver has to do is load those files and not

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boice tomlin

[EMAIL PROTECTED]

503-528-6204

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