Ordinary Kriging Example

First we will create a 2D dataset together with the associated x, y grids.

import numpy as np
import pykrige.kriging_tools as kt
from pykrige.ok import OrdinaryKriging
import matplotlib.pyplot as plt


data = np.array(
    [
        [0.3, 1.2, 0.47],
        [1.9, 0.6, 0.56],
        [1.1, 3.2, 0.74],
        [3.3, 4.4, 1.47],
        [4.7, 3.8, 1.74],
    ]
)

gridx = np.arange(0.0, 5.5, 0.5)
gridy = np.arange(0.0, 5.5, 0.5)

Create the ordinary kriging object. Required inputs are the X-coordinates of the data points, the Y-coordinates of the data points, and the Z-values of the data points. If no variogram model is specified, defaults to a linear variogram model. If no variogram model parameters are specified, then the code automatically calculates the parameters by fitting the variogram model to the binned experimental semivariogram. The verbose kwarg controls code talk-back, and the enable_plotting kwarg controls the display of the semivariogram.

OK = OrdinaryKriging(
    data[:, 0],
    data[:, 1],
    data[:, 2],
    variogram_model="linear",
    verbose=False,
    enable_plotting=False,
)

Creates the kriged grid and the variance grid. Allows for kriging on a rectangular grid of points, on a masked rectangular grid of points, or with arbitrary points. (See OrdinaryKriging.__doc__ for more information.)

z, ss = OK.execute("grid", gridx, gridy)

Writes the kriged grid to an ASCII grid file and plot it.

kt.write_asc_grid(gridx, gridy, z, filename="output.asc")
plt.imshow(z)
plt.show()