enh: rename eddymotion._sklearn -> eddymotion.gpr

* rename the module so that it is picked up by autodoc.
* also fixes minor errors and improves docs.

docs/notebooks/dmri_covariance.ipynb

@@ -24,7 +24,7 @@
     "import matplotlib.pyplot as plt\n",
     "import numpy as np\n",
     "\n",
-    "from eddymotion.model._sklearn import (\n",
+    "from eddymotion.model.gpr import (\n",
     "    compute_pairwise_angles,\n",
     "    exponential_covariance,\n",
     "    spherical_covariance,\n",
@@ -345,7 +345,7 @@
     }
    ],
    "source": [
-    "from eddymotion.model._sklearn import EddyMotionGPR, SphericalKriging\n",
+    "from eddymotion.model.gpr import EddyMotionGPR, SphericalKriging\n",
     "\n",
     "K = SphericalKriging(beta_a=PARAMETER_SPHERICAL_a, beta_l=PARAMETER_lambda)(X_real)\n",
     "K -= K.min()\n",

scripts/dwi_gp_estimation_error_analysis.py

@@ -36,7 +36,7 @@
 import pandas as pd
 from sklearn.model_selection import KFold, RepeatedKFold, cross_val_predict, cross_val_score
 
-from eddymotion.model._sklearn import (
+from eddymotion.model.gpr import (
     EddyMotionGPR,
     SphericalKriging,
 )
@@ -63,7 +63,7 @@ def cross_validate(
         Number of folds.
     n_repeats : :obj:`int`
         Number of times the cross-validator needs to be repeated.
-    gpr : obj:`~eddymotion.model._sklearn.EddyMotionGPR`
+    gpr : obj:`~eddymotion.model.gpr.EddyMotionGPR`
         The eddymotion Gaussian process regressor object.
 
     Returns

scripts/dwi_gp_estimation_simulated_signal.py

@@ -33,7 +33,7 @@
 import numpy as np
 from dipy.core.sphere import Sphere
 
-from eddymotion.model._sklearn import EddyMotionGPR, SphericalKriging
+from eddymotion.model.gpr import EddyMotionGPR, SphericalKriging
 from eddymotion.testing import simulations as testsims
 
 SAMPLING_DIRECTIONS = 200