Merging vector data

[enganga]

 Hello

 

I recently converted a raster Land cover  data-set of an entire country to vector data

The challenge now comes when i try to merge the files of for instance forest land cover class which has

about a million polygons to one polygon.

 

I tried to do this in Arcmap 10.2.2, however it hangs and does not complete the process, the other error is memory error. This i don't get as i have more than 200 gb space on drive c.

 

Kindly if there is any other platform which can assist me complete this process.

 

Regards,

 

Eric Ng

[iceage]

i have similar problem, more than a milion and 1/2 small vectors to 10 groups. I'm converting in Geomedia, it works, slow, but working.

edit:

8gb ram and 10gb free ssd space, working fine...

Edited February 16, 2015 by iceage

[geocentric]

What if you select 100k polygons and merge that, then merge the next 100k and so on.  Then you do a final merge of the 10 big polygons that you have into one.  Instead of merging it all into one from a million. 

[jonah]

do it in qgis. 

 

Start QGIs>open all layers>click Processing Tab Menu>click Toolbox>Go to Grass Commands [158 geoalgorithms]> click + sign to show all the the commands> look for the v.patch-create a new vector map layer by combining other vector map layers. 

 

It may take a while. depends on the computer machine you used. 

Edited February 17, 2015 by jonah

[enganga]

Sergeant let me try this and will share the results i have a Core I7 8gb Ram .

 

Thanks

[bdsmolla]

In ArcGIS ArcMap use dissolve tool based on class field not merge.

[souvik.gis]

You can do this by using Python Script. Follow the script: --

 

import glob
import shapefile
files = glob.glob("*.shp")
w = shapefile.Writer()
for f in files:
r = shapefile.Reader(f)
w._shapes.extend(r.shapes())
w.records.extend(r.records())
w.fields = list(r.fields)
w.save("merged")