Is there a possibility to define the range-value or display the Variogram when you call the SAGA-Kriging-Module from QGIS? Maybe by using the python console?
In the Kriging (e.g. OK) dialogue window, the
Variogram Model option (default:
a + b * x as shown in your posted picture) requires your direct input of the equation.
Some models (Exp, Sph) use Range, whose input parameters are defined as:
- a: Nugget
- b: Difference between Sill and Nugget (i.e. s-n)
- c: Range
(Note that the meaning of
b in the linear model
a + b * x is the slope).
For example, to use popular
Spherical Model (which equation is
a + b * ifelse(x > c, 1, 1.5 * x / c - 0.5 * x^3 / c^3)), simply write it into the
Variogram Model option window with your own parameters like below:
(You'll see my Nugget is 0.214, Sill is 1.774, and Range is 514.4 meters).