On Fri, Apr 1, 2011 at 2:45 PM, daniel mcinerney <[email protected]> wrote: > Hi list, > > I have a query regarding the error matrix produced > using r.kappa (in GRASS 6.4.0 RC6) and hoping that > the following will help someone to replicate my findings. > From what I see, the error matrix is mis-labeling the > rows/columns in the matrix. > Right, I noticed that some months ago, but fixed it only in grass 7. Now also fixed in 6.5 and 6.4 (r45818 and r45819, respectively).
Markus M > Using the spearfish dataset, I digitised 18 points > to create a reference dataset to validate > the classification, in this case the raster 'landcover.orig' > For the purposes of the test and simplicity, I ensured > that the points were located within two landcover classes > (raster values 42 and 81). The following steps were carried out > to generate the output from r.kappa > > > #Create reference dataset > d.where | r.what input=landcover.orig > kappa_test.txt > > For the purposes of this test, I deliberately changed the > landcover class from 42 to 32 in the validation dataset [1] > This will create an off-diagonal value in the error matrix. > > #Create the vector point from ascii and convert to raster > v.in.ascii input=kappa_test output=kapp_test cat=4 > v.to.rast input=kapp_test output=validation use=cat > > #Run r.kappa > r.kappa classification=landcover.orig reference=validation > output=validation.txt > > The output from r.kappa (validation.txt) is below, however, it appears > to me that the matrix is transposed, i.e. the horizontal values > (MAP1) should in fact be vertical. From my interpretation, the error > matrix indicates that 8 validation points with the value 42 were > classified as 32, but in fact it should state that 8 points with > the value of 32 were classified as 42? Can anyone confirm > my findings? > > Thanks in advance. > > Regards, > Daniel. > > > ACCURACY ASSESSMENT > LOCATION: spearfish60 Fri Apr 1 12:45:42 2011 > MASK: none > MAPS: MAP1 = Categories (validation in user1) > MAP2 = (untitled) (landcover.orig in PERMANENT) > > Error Matrix > Panel #1 of 1 > MAP1 > cat# 32 42 81 Row Sum > M 32 0 8 0 8 > A 42 0 0 0 0 > P 81 0 0 10 10 > Col Sum 0 8 10 18 > > > Cats % Commission % Ommission Estimated Kappa > 32 100.000000 -nan -999.000000 > 42 NA NA NA > 81 0.000000 0.000000 1.000000 > > Kappa Kappa Variance > 0.357143 0.002343 > > Obs Correct Total Obs % Observed Correct > 10 18 55.555556 > > > > [1] > #validation input > 590188.6875|4919453.8125||32 > 590188.6875|4918947||32 > 590307.9375|4918350.75||32 > 590576.25|4917694.875||32 > 590307.9375|4917694.875||32 > 590546.4375|4919364.375||32 > 590874.375|4919364.375||32 > 590904.1875|4919483.625||32 > 603604.3125|4922047.5||81 > 603336|4922315.8125||81 > 603514.875|4922464.875||81 > 603604.3125|4922256.1875||81 > 603634.125|4922107.125||81 > 603693.75|4921987.875||81 > 603962.0625|4921987.875||81 > 603753.375|4921600.3125||81 > 603962.0625|4922047.5||81 > 598983.375|4922256.1875||81 > > > > > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user > > _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
