question about shp2tile
Stephen Woodbridge
woodbri at SWOODBRIDGE.COM
Thu May 18 21:22:22 EDT 2006
Zhonghai,
Here is a log of what I did. I always make a directory to put the tiles
into, woodland for this example.
> woodbri at linus:~/test$ ls
> CA_NAV_COUNTRY_region.dbf CA_NAV_WOODLAND_region.prj
> CA_NAV_COUNTRY_region.prj CA_NAV_WOODLAND_region.qix
> CA_NAV_COUNTRY_region.qix CA_NAV_WOODLAND_region.shp
> CA_NAV_COUNTRY_region.shp CA_NAV_WOODLAND_region.shx
> CA_NAV_COUNTRY_region.shx test.rar
> CA_NAV_WOODLAND_region.dbf
make a dir for the tiles
> woodbri at linus:~/test$ mkdir woodland
> woodbri at linus:~/test$ shp2tile
> Usage: shp2tile <options> <shapefile> <dest name>
> where <options> are:
> [-v|--version] print version string and exit
> [-s|--no-stats] do not print stats
> [-w|--no-write] do not write output files
> [-r|--row] <n> generate <n> rows in Y
> [-c|--col] <m> generate <m> cols in X
> [-e|--square-ext] adjust extent to produce square tiles
> [-q|--quadtree] <n> quadtree type of index (auto split tiles > n objects)
> <shapefile> name of file to read and split into tiles
> <dest name> output file names: <dest name>-<num>.<ext>
check how big the shapfile is
> woodbri at linus:~/test$ shpdump CA_NAV_WOODLAND_region | head
> Shapefile Type: Polygon # of Shapes: 9638
>
> File Bounds: ( 6.055, 45.818,0,0)
> to ( 10.489, 47.808,0,0)
>
> Shape:0 (Polygon) nVertices=62, nParts=1
> Bounds:( 7.602, 47.573, 0, 0)
> to ( 7.627, 47.579, 0, 0)
> ( 7.609, 47.578, 0, 0) Ring
> ( 7.610, 47.578, 0, 0)
check that I am working with the most recent version
> woodbri at linus:~/test$ shp2tile -v
> $Id: shp2tile.c,v 1.13 2005/12/05 22:38:08 woodbri Exp $
run a test -w says down write tiles, just print stats
> woodbri at linus:~/test$ shp2tile -r 3 -c 3 -w CA_NAV_WOODLAND_region.shp woodland/woodland
> Shapefile Type: Polygon # of Shapes: 9638
>
> File Bounds: ( 6.055040, 45.818020)
> to ( 10.489220, 47.808380)
>
> Divided into 3 rows X 3 columns (dx, dy) = ( 1.478060, 0.663453)
>
> Index Cell Count XMin YMin YMax YMax
> 0 [ 0, 0] 1062 6.055040 45.818020 7.533100 46.481473
> 1 [ 0, 1] 1867 7.533100 45.818020 9.011160 46.481473
> 2 [ 0, 2] 556 9.011160 45.818020 10.489220 46.481473
> 3 [ 1, 0] 888 6.055040 46.481473 7.533100 47.144927
> 4 [ 1, 1] 1206 7.533100 46.481473 9.011160 47.144927
> 5 [ 1, 2] 2059 9.011160 46.481473 10.489220 47.144927
> 6 [ 2, 0] 100 6.055040 47.144927 7.533100 47.808380
> 7 [ 2, 1] 1413 7.533100 47.144927 9.011160 47.808380
> 8 [ 2, 2] 475 9.011160 47.144927 10.489220 47.808380
> 9 [ global] 12 6.055040 45.818020 10.489220 47.808380
> --------
> 9638
> Global cell contains: 0 objects.
These are too small a cound so do the 2 x 2
> woodbri at linus:~/test$ shp2tile -r 2 -c 2 -w CA_NAV_WOODLAND_region.shp woodland/woodland
> Shapefile Type: Polygon # of Shapes: 9638
>
> File Bounds: ( 6.055040, 45.818020)
> to ( 10.489220, 47.808380)
>
> Divided into 2 rows X 2 columns (dx, dy) = ( 2.217090, 0.995180)
>
> Index Cell Count XMin YMin YMax YMax
> 0 [ 0, 0] 3096 6.055040 45.818020 8.272130 46.813200
> 1 [ 0, 1] 2751 8.272130 45.818020 10.489220 46.813200
> 2 [ 1, 0] 1679 6.055040 46.813200 8.272130 47.808380
> 3 [ 1, 1] 2107 8.272130 46.813200 10.489220 47.808380
> 4 [ global] 5 6.055040 45.818020 10.489220 47.808380
> --------
> 9638
> Global cell contains: 0 objects.
Now really do the 2x2 and write the files
> woodbri at linus:~/test$ shp2tile -r 2 -c 2 CA_NAV_WOODLAND_region.shp woodland/woodland
> Shapefile Type: Polygon # of Shapes: 9638
>
> File Bounds: ( 8.272390, 46.764400)
> to ( 10.489220, 47.808380)
>
> Divided into 2 rows X 2 columns (dx, dy) = ( 2.217090, 0.995180)
>
> Index Cell Count XMin YMin YMax YMax
> 0 [ 0, 0] 3096 6.055040 45.909350 8.277650 46.859200
> 1 [ 0, 1] 2751 8.274860 45.818020 10.479450 46.834150
> 2 [ 1, 0] 1679 6.432630 46.783620 8.373900 47.613070
> 3 [ 1, 1] 2107 8.272390 46.764400 10.489220 47.808380
> 4 [ global] 5 6.055040 45.818020 10.489220 47.808380
> --------
> 9638
> Global cell contains: 5 objects.
list the new files
> woodbri at linus:~/test$ ls woodland/
> woodland-0.dbf woodland-1.dbf woodland-2.dbf woodland-3.dbf woodland-4.dbf
> woodland-0.shp woodland-1.shp woodland-2.shp woodland-3.shp woodland-4.shp
> woodland-0.shx woodland-1.shx woodland-2.shx woodland-3.shx woodland-4.shx
create the spatial indexes
> woodbri at linus:~/test$ find woodland/ -name \*.shp -exec shptree {} \;
> creating index of new LSB format
> creating index of new LSB format
> creating index of new LSB format
> creating index of new LSB format
> creating index of new LSB format
create the metatile input file
> woodbri at linus:~/test$ find woodland/ -name \*.shp > woodland.in
check the command syntax
> woodbri at linus:~/test$ tile4ms
>
> usage: tile4ms <meta-file> <tile-file> [-tile-path-only]
> <meta-file> INPUT file containing list of shapefile names
> (complete paths 255 chars max, no extension)
> <tile-file> OUTPUT shape file of extent rectangles and names
> of tiles in <tile-file>.dbf
> -tile-path-only Optional flag. If specified then only the path to the
> shape files will be stored in the LOCATION field
> instead of storing the full filename.
>
create the tileindex
> woodbri at linus:~/test$ tile4ms woodland.in woodland-tile
> Processed 5 of 5 files
See what we have got
> woodbri at linus:~/test$ ls
> CA_NAV_COUNTRY_region.dbf CA_NAV_WOODLAND_region.shx
> CA_NAV_COUNTRY_region.prj county
> CA_NAV_COUNTRY_region.qix test.rar
> CA_NAV_COUNTRY_region.shp woodland
> CA_NAV_COUNTRY_region.shx woodland-tile.dbf
> CA_NAV_WOODLAND_region.dbf woodland-tile.shp
> CA_NAV_WOODLAND_region.prj woodland-tile.shx
> CA_NAV_WOODLAND_region.qix woodland.in
> CA_NAV_WOODLAND_region.shp
Oh, add spatial index to the tileindex
> woodbri at linus:~/test$ shptree woodland-tile.shp
> creating index of new LSB format
check the country file size
> woodbri at linus:~/test$ shpdump CA_NAV_COUNTRY_region.shp | head
> Shapefile Type: Polygon # of Shapes: 5
>
> File Bounds: ( 5.956, 45.818,0,0)
> to ( 10.492, 47.808,0,0)
>
> Shape:0 (Polygon) nVertices=15977, nParts=3
> Bounds:( 5.956, 45.818, 0, 0)
> to ( 10.492, 47.808, 0, 0)
> ( 10.047, 46.544, 0, 0) Ring
> ( 10.047, 46.543, 0, 0)
country file is too small to index.
Make a mapfile to view the results:
MAP
EXTENT 5.956 45.818 10.492 47.808
IMAGECOLOR 240 204 102
SHAPEPATH /u/test
SIZE 600 400
UNITS DD
LAYER
NAME "administration"
GROUP "country"
STATUS DEFAULT
DATA "CA_NAV_COUNTRY_region"
TYPE POLYGON
DEBUG ON
CLASS
NAME "country"
STYLE
COLOR 255 255 204
END
END
END
LAYER
NAME "woodland"
GROUP "country"
STATUS DEFAULT
TILEINDEX "woodland-tile"
TYPE POLYGON
DEBUG ON
CLASS
NAME "woodland"
STYLE
COLOR 102 255 102
END
END
END
END
Here is a url to see the results.
http://swoodbridge.com/linus/cgi-bin/mapserv461?mode=map&map=/u/test/test.map
you should be able to do the same and get the same results.
-Steve
Zhonghai Wang wrote:
> Hi Steve,
>
> the example shapefiles are enclosed in the attachment as a .rar file,
> the coordinate system is swiss national system, epsg:21781 or world:CH1903.
>
> specify any parameter values won't work, only using default 2*2 images
> can be rendered, as I said, only part of the map extent.
>
> thanks
>
> zhongahi
>
> On 5/18/06, *Stephen Woodbridge* < woodbri at swoodbridge.com
> <mailto:woodbri at swoodbridge.com>> wrote:
>
> Zhonghai,
>
> Can you send me the forest and settlement shap files.
>
> tar czf data-for-steve.tgz forest.* settlement.*
>
> and email me the file. I will take a look. It might be a bug.
>
> -Steve
>
> Zhonghai Wang wrote:
> > Hi All,
> >
> > with the shp2tile command, I get some strange results:
> >
> > data -- forests.shp (includes 9638 polygons) -- only used for example
> >
> > after performing the commands shp2tile, tile4ms and shptree, this
> time I
> > perform additionally the command shptreevis for each shapefile,
> and I
> > get the quadtree views for the shapefiles. When I open the
> > forest_quad.shp and overlay the tileindex_quad.shp on it with
> QGIS, the
> > tileindex_quad.shp covers only a small part of the whole forest map
> > extent, and the returned map image is rendered in the same way,
> forest
> > covers only a small part of the map extent.
> >
> > P.S>I tile the shapefile without any additional parameters: shp2tile
> > forests.shp ff.shp -- it gives 2*2 tiling
> >
> > two pictures are enclosed in the attachment.
> >
> > where:
> > 1. quadtree.jpeg -- the quadtree shapefiles opened in QGIS;
> > 2. map.jpeg -- map image rendered with TILEINDEX "tileindex" and
> > TILEITEM "LOCATION";
> > 3. forest.jpeg -- forest area rendered with original forests.shp
> file.
> >
> > thanks for any further info
> >
> > zhonghai
> >
> > On 5/18/06, *Zhonghai Wang* < zhonghaiw at gmail.com
> <mailto:zhonghaiw at gmail.com>
> > <mailto: zhonghaiw at gmail.com <mailto:zhonghaiw at gmail.com>>> wrote:
> >
> > Hi Steve,
> >
> > I've tried again like you said, this time I get something,
> but still
> > no map images are rendered.
> >
> > the version is exactly the same, updated version.
> >
> > First test example:
> >
> > data -- admin.shp (administration area, which includes 5
> polygons)
> >
> > ****
> > when performing shp2tile command, no parameters are set, and by
> > default the shapefile is sliced into 2*2+1 shapefiles. With the
> > following layer object definition, map image is drawn:
> >
> > LAYER
> > NAME "administration"
> > GROUP "country"
> > STATUS DEFAULT
> > TILEINDEX "index"
> > TILEITEM "LOCATION"
> > TYPE POLYGON
> > DEBUG ON
> > TRANSPARENCY ALPHA
> > CLASS
> > NAME "woodland"
> > STYLE
> > COLOR 204 204 255
> > ANTIALIAS TRUE
> > END
> > END
> > END
> > **********
> > Second test example:
> >
> > data -- settlement.shp, which contains 2155664 polygons
> >
> > ****
> > when performing shp2tile command for this shapefile, I set 10*10,
> > each slice contians therefore about 21557 polygons. It's also ok
> > with tile4ms and shptree commands.
> >
> > hm... seems exciting...
> >
> > but, with this layer object definition no settlements are drawn :
> >
> > LAYER
> > NAME "Settlement"
> > GROUP "settlements"
> > STATUS DEFAULT
> > TILEINDEX "settlementindex"
> > TILEITEM "LOCATION"
> > MAXSCALE 100000
> > TYPE POLYGON
> > DEBUG ON
> > TRANSPARENCY ALPHA
> > CLASS
> > NAME "SM"
> > STYLE
> > COLOR 153 153 102
> > ANTIALIAS TRUE
> > END
> > END
> > END
> > *****
> > I have now really no idea where the problems should be.
> >
> > Steve, any clues?
> >
> > thanks for your info.
> >
> > zhonghai
> >
> > On 5/18/06, *Stephen Woodbridge* <woodbri at swoodbridge.com
> <mailto:woodbri at swoodbridge.com>
> > <mailto: woodbri at swoodbridge.com
> <mailto:woodbri at swoodbridge.com>>> wrote:
> >
> > Zhonghai Wang wrote:
> >> Hi guys,
> >>
> >> I've tried to make a efficient map layer with the commands
> > shp2tile,
> >> tile4ms, and shptree, but something seems not right, because
> > MapServer
> >> can not draw the maps. I've made a test in a seperate folder,
> > and I've
> >> done the following processes:
> >>
> >> ***
> >> data -- Forests.shp (for a country)
> >> ***
> >> 1. >shp2tile -r 50 -c 50 Forests.shp Forests_Test.shp
> >> >>>results for this step: shp, shx, and dbf files, there is no
> > prj file
> >> for the output file
> >> >>>error info on the console: failed to create shp
> > Forests_Test.shp -1833
> >
> > This is likely because you are trying to create 2501
> files (50 x
> > 50 + 1)
> > and they all half to be open at the same time for this
> mode so you
> > likely ran into a process file handle limit. Also how
> many point
> > do you
> > have in this layer? What is the value of Num_points/2500,
> this
> > number
> > should not be smaller than 8000 - 10000.
> >
> >> 2. >tile4ms ---- get the tileindex.shx, tileindex.shp and
> > tileindex.dbf
> >> files for the Forests_Test.shp, there is still no prj file for
> > tileindex.shp
> >> >>>no error messages appear at this step
> >
> > There are no prj files created. Mapserver does not use them.
> >
> >> 3. >shptree -- to genetare .qix file for all shapefiles in
> > this subfolder
> >> >>> results for this step: Forests.qix, Forests_Test.qix, and
> > tileindex.qix
> >> >>>no error info on the console
> >>
> >> but, only if I set DATA "Forests" in the layer object the map
> > will be
> >> rendered, others like DATA "Forests_Test" or TTILEINDEX
> > "tileindex"
> >> TILEITEM "location" do not work, the server simply sends back
> > a blank
> >> image.
> >>
> >> did I make any mistakes or it really do not work well. (I am
> > using MS4W
> >> 4.8.1)
> >>
> >> I guess some errors occur when I perform the command shp2tile.
> >
> > What version of shp2tile are you using?
> >
> > woodbri at carto:/data/mdata$ ~/dev/shptools/shp2tile -v
> > $Id: shp2tile.c,v 1.13 2005/12/05 22:38:08 woodbri Exp $
> >
> > If it does not respond with the Id string above you need to
> > upgrade as
> > there is a serious crashing bug for point data in the earlier
> > version if
> > you are using the -q option. It should work for the row col
> > option, just
> > try to decrease the number of tiles.
> >
> > Also if you do not have something like R x C files in
> your directory
> > then the process failed. For the row col option you can also
> > specify
> > --no-write to just get a stats report of how the data is put
> > into the tiles.
> >
> > -Steve
> >
> >> thanks for any further info.
> >>
> >> zhonghai
> >>
> >> On 5/18/06, *Zhonghai Wang* < zhonghaiw at gmail.com
> <mailto:zhonghaiw at gmail.com>
> > <mailto: zhonghaiw at gmail.com <mailto:zhonghaiw at gmail.com>>
> >> <mailto:zhonghaiw at gmail.com <mailto:zhonghaiw at gmail.com>
> <mailto: zhonghaiw at gmail.com <mailto:zhonghaiw at gmail.com>>>> wrote:
> >>
> >> Hi Bob, Steve,
> >>
> >> thank you very much for all these helpful clues, now I
> > think I've
> >> got the points of the shp2tile command, it's really a good
> > tool to
> >> slice shapefile.
> >>
> >> zhonghai
> >>
> >> On 5/18/06, *Stephen Woodbridge* < woodbri at swoodbridge.com
> <mailto:woodbri at swoodbridge.com>
> > <mailto: woodbri at swoodbridge.com
> <mailto:woodbri at swoodbridge.com>>
> >> <mailto: woodbri at swoodbridge.com
> <mailto:woodbri at swoodbridge.com>
> > <mailto: woodbri at swoodbridge.com
> <mailto:woodbri at swoodbridge.com> >>> wrote:
> >>
> >> Zhonghai Wang wrote:
> >> > Hi folks,
> >> >
> >> > I have a large shapefile, now I am trying to use shp2tile
> >> command to
> >> > slice it into pieces, with -r and -c is ok, but I do not fully
> >> > understand the -q parameter, what does it actually mean? and
> >> what number
> >> > should a use for this parameter normally?
> >> >
> >> > or something like this? -- >shp2tile -q 10000 input_shapefile
> >> > output_shapefile
> >>
> >> Hi Zhonghai,
> >>
> >> The -r -c option breaks the extents of your shapefile
> > into R x C
> >> rows
> >> and columns and then tries to fit the objects into the best
> >> tile. I any
> >> tile crosses a tile boundary by 5-10% then it is put
> > into a
> >> "supertile"
> >> the could be the same extents as the original shape
> > file. So
> >> typically
> >> you will end up with r X c + 1 tiles.
> >>
> >> The -q N option splits the extents in half either
> > vertically or
> >> horizontally and then sorts the objects into the 2
> > halves or put
> >> them in
> >> a supertile. Then if the either of the two halves has
> > more than N
> >> objects it is again split in half and this continues
> > until all files
> >> have less than N objects. This can cause some strange
> > effects
> >> like tiles
> >> with 1 or a small number of objects and most tiles will
> > have
> >> less than N
> >> objects in them. Since this algorithm tends to
> > spatially cluster
> >> objects
> >> in a file, there is a good chance that if you need the
> > file that
> >> all or
> >> most objects in the file will be used.
> >>
> >> I recommend trying numbers like 10,000 and 20,000 as
> > you initial
> >> tries.
> >> I think you should probably not use numbers less then
> > 8000, but
> >> it is
> >> really up to you to try and measure the results to find
> > what
> >> works best
> >> for your data.
> >>
> >> -Steve W.
> >>
> >>
> >>
> >
> >
> >
> >
> >
> ------------------------------------------------------------------------
> >
> >
> >
> ------------------------------------------------------------------------
>
> >
> >
> >
> ------------------------------------------------------------------------
> >
>
>
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