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"Whilst calculating the average of the cell a weighted distance value will be assigned to all neighboring points within the cell. In case of the max value not being located in the center of the cell, it will be weighted according to its distance from the center of the cell and nearby points. Hence the max value does not show up as the final cell value. Is this right?"
I'm interested in knowing the answer to this specific part of this person's question, and what if my point is a physical sample location with analytical results (i.e. metals, petroleum, etc.) and I need to preserve these values?
I believe in my case, by making the measurement error = 0 during kriging I've made it an exact interpolator - is that a correct assumption?
And if so what's the process to preserve these "exact" values at my sample locations in the exported raster then if there's always going to be some averaging going on to get to a cell size, what if my sample point is not exactly in the center - is there a way to center them? It seems I've seen this in my resultant rasters where the values at my sample locations are not honored but "averaged over" during cell creation/export - could someone explain the process in this context, wherein I can preserve the exact max/min of and values of my samples at their locations?
I read your explanation. My simple kriging surface gives values ranging from -5.1 to 2.17. When I transform my simple kriging surface into a raster the values range from -3.59 to 1.49. That is OK because it is within the range above (i.e. -5.1 to 2.17).
My universal kriging surface gives values ranging from -5.1 to 2.17. When I transform my universal kriging surface into a raster the values range from - 29.17 to 37.83. That is not OK because it is out of the range above (I.e., -5.1 to 2.17). For this one the ranges are too different. Any comments?
Best regards, Monica.
Are there settings/environments/etc to maintain original value of input points. Important for analysis. For example, we have input point file that has a maximum value of 218, yet the resultant GA Layer and exported raster cell values at that point are in the 90's. And the maximum value of the raster is 108 - half of the original point data :
In order for the geostatistical layer to pass through the input points perfectly, you can use IDW or Radial Basis Functions. They are exact interpolators, and they will always pass through the input points. If you are using kriging (other than Empirical Bayesian Kriging), you can force it to be an exact interpolator by turning off the nugget effect. In the Geostatistical Wizard on the semivariogram page, look for the "Model Nugget" section and disable the nugget effect.
However, you should know that forcing an interpolation method to be exact can sometimes result in strange artifacts in the surface. Make sure to look at your surface carefully.