[STATSGRASS] different kriging results with the same parameters
Carlos "Guâno" Grohmann
carlos.grohmann at gmail.com
Fri Nov 3 16:34:28 EST 2006
I was kriging some SRTM DEMs, and I noticed that I get different
results with the same parameters!!
check out:
summary(srtm) - original data
Data attributes:
band1
Min. : 634.0
1st Qu.: 759.0
Median : 814.0
Mean : 856.5
3rd Qu.: 923.0
Max. :1312.0
vrg.eye<-(vgm(psill=950, model="Gau", range=245, nugget=6.2));
OK_pred_md250 <- krige(srtm$band1 ~ 1, loc=srtm2, newdata=mask_SG,
model=vrg.eye, maxdist=250);
summary(OK_pred_md250);
Data attributes:
var1.pred var1.var
Min. : 632.8 Min. : 8.054
1st Qu.: 759.2 1st Qu.: 8.576
Median : 814.3 Median : 8.712
Mean : 856.4 Mean : 9.052
3rd Qu.: 923.6 3rd Qu.: 8.865
Max. :1307.6 Max. :395.609
Data attributes:
var1.pred var1.var
Min. : 632.4 Min. : 8.040
1st Qu.: 759.2 1st Qu.: 8.577
Median : 814.3 Median : 8.711
Mean : 856.4 Mean : 9.048
3rd Qu.: 923.6 3rd Qu.: 8.863
Max. :1306.2 Max. :341.567
Data attributes:
var1.pred var1.var
Min. : 632.9 Min. : 8.039
1st Qu.: 759.2 1st Qu.: 8.576
Median : 814.3 Median : 8.712
Mean : 856.4 Mean : 9.052
3rd Qu.: 923.6 3rd Qu.: 8.865
Max. :1306.9 Max. :345.084
>
So, the minimum and maximum have changed each time. Why?
thanks
--
+-----------------------------------------------------------+
Carlos Henrique Grohmann - Guano
Geologist M.Sc - Doctorate Student at IGc-USP - Brazil
Linux User #89721 - carlos dot grohmann at gmail dot com
+-----------------------------------------------------------+
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