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I using arcgis10.1 extract by mask tool to clip bkgha1 raster with rubber2012 vecotor layer,clipping process is successful and the result is bkgha file.The next process is i want to reclassify the bkgha file (using reclassify spataial analsyst tool of arcgis10.1) with 2 sub divsions,That process also sucessful.


The reclassified output class is 1) 279837 2) 95834 Total Area 33810.39 hectre Problems:

My input rubber2012 vector Total Area is 38997.64.. 38997.64-33810.39= 5187 hectre mismach is occured why?(less mismatch is ok but its huge mismatch).please give a solution.

I am sending below link for input and out files please check Rubber2012:vector bkgha1:30m tif is input bkgha: my cliped output

https://drive.google.com/folderview?id=0By0CgkNTboOXdzZQd3ZWS29aLTg&usp=sharing

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If you are talking about a mismatch in the area between the vector layer and the resulting clipped raster, the likely cause is because a vector is a representation of continuous space, that is areas can be of any size, while a raster is a representation of discrete space, that is an area can only be sizes that are multiples of the pixel size. For example, if you had a 9 square km polygon and you were clipping a raster with 10 square km pixels, the smallest area you could get in the resulting raster would be 10 square km, or 1 pixel, assuming there is an intersection between the extents of the polygon and raster.

  • ok that's true.but am working with different districts most are likely matching with vector area and clipped reclassifysubclasses(only slightly less deviation means max 1000 hectc deviation but this is 5000hetcre so this classification is not near by my input and output comparison) – SANJU Nov 11 '15 at 10:23
  • Yes, you have to remember that the clipped raster will be a 'rectangular' shape the same size as the extents of the vector layer. Therefore you will have some pixels that will be NA values (where they do not coincide with the polygon) that you may have reclassified by mistake. – Sam Nov 11 '15 at 10:23
  • ok.actually you are saying there is no mistake in my process? only the vector to raster conversion pixel error correction happened and that is the mismatch comes.true – SANJU Nov 11 '15 at 10:46
  • im not sure exactly on your method, i cannot download your data, perhaps you can zip it all to one file and i can check – Sam Nov 11 '15 at 10:53
  • ok..zip file : drive.google.com/open?id=0By0CgkNTboOXdl9hYy1FZGFEOE0 – SANJU Nov 11 '15 at 10:58

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