need mapserv.exe recompiled with max layers= 500

[Ravi]

Yes it makes sense. However...here is the catch.

I do not know how to add 'population' attribute to be able to do the 
comparison you mentioned. I also tried to get PostGIS working, I get no 
errors, I have checked all configuration but no maps show up.

So can you throw some light on how to add 'population' of each county 
inside each shapefile so that I can do the comparison you mentioned? In 
absence of that either I select each county individually (slow) or do 
what I am doing now which is create files as follows and create one 
layer for each file:

PopulationCountyColor1.shp
PopulationCountyColor2.shp
...
...
PopulationCountyColor10.shp
PopulationZipCodeColor1.shp
..
...
GrowthZipCodeColor10.shp

These come out to be a total of 240 files (8x3x10, 8 parameters, 3 
shapes and 10 colors).

Regards
Ravi


Delfos, Jacob wrote:
> Yes, but I figured there had to be a reason why you are selecting each 
> county individually, resulting in slow performance if you combine ten 
> classes into a layer. If you have only got 300 objects that require 
> classifying, then having ten classes should really not be a drama. Of 
> course if you classify each object individually, then it becomes 
> expensive (300 comparisons with 300 objects times 10 = 900,000 
> comparisons: SLOW). But if you use ranges (e.g. ('[population]'>100) AND 
> ('[population]'<200)   ) then you reduce it to 600 comparisons per 
> class, meaning 6000 comparisons for a layer. That's way less than 900,000.
> 
> Does this make sense in your scenario?
> 
> 
> -----Original Message-----
> From: Ravi [mailto:ravikapoor101 at gmail.com]
> Sent: Wed 12/6/2006 3:13 PM
> To: Delfos, Jacob
> Cc: MAPSERVER-USERS at LISTS.UMN.EDU
> Subject: Re: [UMN_MAPSERVER-USERS] need mapserv.exe recompiled with max 
> layers= 500
> 
> 
> Hi Jacob,
> 
> I am doing pre-generation of layers. I thought each layer has to be a
> separate shape file and need a separate "LAYER" tag. Is that not so?
> 
> Thanks for your thoughts
> Ravi
> 
> 
> Delfos, Jacob wrote:
>  > Ravi,
>  >
>  > Why do you select out each county individually, rather than having an 
> expression that defines a range of population density? For example, 
> EXPRESSION ('[populationdensity]'>500)
>  >
>  > If you can't do that, do you have the ability to pre-generate the 
> classified layers, such that each layer requires no further 
> classification, and contains a class (1 through to 10) of which colour 
> it should have?
>  >
>  > If even that fails, you could consider rendering your areas to a 
> raster, and only start showing individual vector-based objects when a 
> user zooms in. I have used that approach to 'fake' the displaying of 
> 100,000s of polygons, so that they wouldn't have to be generated at 
> runtime. You  can use minscale and maxscale to turn the raster off when 
> the vector comes in.
>  >
>  > Otherwise, can you tell us what datasource you are using? Shapefiles? 
> PostGIS?
>  >
>  > regards,
>  >
>  > Jacob
>  >
>  >
>  >
>  >
>  >
>  > -----Original Message-----
>  > From: UMN MapServer Users List on behalf of Ravi
>  > Sent: Wed 12/6/2006 2:41 PM
>  > To: MAPSERVER-USERS at LISTS.UMN.EDU
>  > Subject: [UMN_MAPSERVER-USERS] need mapserv.exe recompiled with max 
> layers = 500
>  > 
>  > Hi,
>  >
>  > Can somebody recompile the mapserv.exe with max layers = 500? Or guide
>  > me how to do this? If you want to charge for this kind of service, can
>  > you send me an email telling me how much would you charge?
>  >
>  > Yes I have thought about reducing the layers and tried various options
>  > to the best of my knowledge but so far I have not come up with a 
> solution.
>  >
>  > If you are curious why I need so many layers or can help me reduce
>  > layers here is what I am doing. This is very confusing...sorry I am
>  > trying my best to explain.
>  >
>  > I want to show population density in US using 10 different colors. Hence
>  > I need 10 layers (1 for each color). I am not able to use single layer
>  > as I would need to define 10 classes with different colors. Each class
>  > will select 300 counties using "EXPRESSION" as follows:
>  > EXPRESSION ('[FIPSSTCO]'='21037' or '[FIPSSTCO]'='21125' or.....
>  > Selecting 300 counties like this is VERY slow.
>  >
>  > Now we can see entire US map with colors. When the user zooms in, I have
>  > to show same thing using zip codes. Further zooming in shows the data
>  > divided by block groups. Hence total layers = 10x3 = 30.
>  >
>  > Now I need to show 8 such parameters (potentially 16). Hence I need
>  > 10x3x16 = 480 layers
>  >
>  > Thanks for help
>  > Ravi
>  >
> 
>