From d44345ee28e270f7be32b32616ea2c5f1984c4b1 Mon Sep 17 00:00:00 2001
From: MuellerSeb <mueller.seb@posteo.de>
Date: Mon, 30 Dec 2019 01:50:25 +0100
Subject: [PATCH] Examples: add examples for universal and ext-drift kriging

---
 examples/21_extdrift_kriging.py  | 20 ++++++++++++++++++++
 examples/22_universal_kriging.py | 20 ++++++++++++++++++++
 2 files changed, 40 insertions(+)
 create mode 100755 examples/21_extdrift_kriging.py
 create mode 100755 examples/22_universal_kriging.py

diff --git a/examples/21_extdrift_kriging.py b/examples/21_extdrift_kriging.py
new file mode 100755
index 00000000..f297eb33
--- /dev/null
+++ b/examples/21_extdrift_kriging.py
@@ -0,0 +1,20 @@
+import numpy as np
+from gstools import SRF, Gaussian, krige
+
+# condtions
+drift_model = Gaussian(dim=1, len_scale=4)
+drift = SRF(drift_model, seed=1010)
+cond_pos = [0.3, 1.9, 1.1, 3.3, 4.7]
+ext_drift = drift(cond_pos)
+cond_val = ext_drift * 2 + 1
+# resulting grid
+gridx = np.linspace(0.0, 15.0, 151)
+grid_drift = drift(gridx)
+# spatial random field class
+model = Gaussian(dim=1, var=2, len_scale=4)
+krig = krige.ExtDrift(model, cond_pos, cond_val, ext_drift)
+krig(gridx, ext_drift=grid_drift)
+ax = krig.plot()
+ax.scatter(cond_pos, cond_val, color="k", zorder=10, label="Conditions")
+ax.plot(gridx, grid_drift, label="drift")
+ax.legend()
diff --git a/examples/22_universal_kriging.py b/examples/22_universal_kriging.py
new file mode 100755
index 00000000..25222a24
--- /dev/null
+++ b/examples/22_universal_kriging.py
@@ -0,0 +1,20 @@
+import numpy as np
+from gstools import SRF, Gaussian, krige
+
+# condtions
+drift_model = Gaussian(dim=1, var=0.1, len_scale=2)
+drift = SRF(drift_model, seed=101)
+cond_pos = np.linspace(0.1, 8, 10)
+cond_val = drift(cond_pos) + cond_pos * 0.1 + 1
+# resulting grid
+gridx = np.linspace(0.0, 15.0, 151)
+drift_field = drift(gridx) + gridx * 0.1 + 1
+# spatial random field class
+model = Gaussian(dim=1, var=0.1, len_scale=2)
+krig = krige.Universal(model, cond_pos, cond_val, "linear")
+krig(gridx)
+ax = krig.plot()
+ax.scatter(cond_pos, cond_val, color="k", zorder=10, label="Conditions")
+ax.plot(gridx, gridx * 0.1 + 1, label="linear drift")
+ax.plot(gridx, drift_field, "--", label="original field")
+ax.legend()