Shptree notes

shptree Processing Notes

(for the Benchmarking_2010 exercise)

shptree Depth

No depth parameter was used for the shptree command, which means the shptree code would determine the optimal depth. The determined depths were:

file	depth
building	21
contour-0	16
contour-1	17
contour-2	17
contour-3	17
contour-4	17
contour-5	15
contour-6	17
contour-7	17
industry	17
motorway	10
point-labels-for-geometry	15
point-labels-no-geometry	18
ramp	14
road	14
settlement	16
track	16

Verifying the qix file

• shptreetst utility was used to verify the integrity of qix file
• you should see a message like:

 $ shptreetst contour-0.qix 

 This new LSB index supports a shapefile with 221671 shapes, 16 depth 
 shapes 0, node 4, -8.187613,36.166759,3.274251,43.666687 
 shapes 0, node 4, -8.187613,36.166759,-1.883588,40.291719 
 shapes 0, node 4, -8.187613,36.166759,-4.720399,38.435487 
 shapes 0, node 1, -8.187613,36.166759,-6.280646,37.414560 
 shapes 0, node 2, -7.329478,36.728269,-6.280646,37.414560 
 ... 
 
 read entire file now at quad box rec 20 file pos 1000
 using last read box as a search 
 result of rectangle search was 
   86554, 86580, 86586, 86598, 86638, 86641, 86642, 86643, 86660, 86667, 195862, 195895, 195901, 195903, 195926, 196873, 197711,

buildings.shp

• shptreetst building.qix caused a Segmentation fault initially on our BenchmarkB Linux server (with 8GB RAM)
• to solve this we...

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