[ka-Map-users] Calculating number of tiles in cache

[Paul Spencer]

Shoaib,

the maximum size of the tile cache for a given kaMap installation  
could be calculated from:

total = 0
for each map file
{
     for each scale
     {
         for each separate group in the map file
         {
              convert geographic extents to pixels at this scale
              divide width and height by tile width and height
              multiple number of tiles wide by high
              add to total
         }
     }
}

Tile size on disk depends on output format generally, and also on  
image complexity in compressed formats like PNG.  You'll probably  
need to do a random sampling at each scale to get a good average

Cheers

Paul

On 2-Feb-06, at 7:47 AM, Shoaib Burq wrote:

> Hi
>
> I am trying to estimate the potential size of ka-map cache.
>
> Not so sure about the math to calculate the number of tiles given:
>
> 1. Area of the region
> 2. Raster Resolution
> 3. Tile Size
> 4. Num of Layers
>
> any suggestions?
>
> Also what's a good way to estimate the size of each tile on disk?
>
> thanks heaps
> shoaib
>
> _______________________________________________
> ka-Map-users mailing list
> ka-Map-users at lists.maptools.org
> http://lists.maptools.org/mailman/listinfo/ka-map-users
>

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|Paul Spencer                           pspencer at dmsolutions.ca   |
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|Applications & Software Development                              |
|DM Solutions Group Inc                 http://www.dmsolutions.ca/|
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