Addressing issue number #470 (using plot_kde with inference data obje…

…ct) (#600)

* Made the following additions:
 * Using inference data or xr.dataset with plot_kde now raises an error prompting user to use plot_posterior instead.
 * Rug plots displayed by default for plot_posterior plots.
 * Not included the tests yet.

* Added the test

* Made the suggested changes.

* fixed load_arviz_data import

* Made the following additions:
 * Using inference data or xr.dataset with plot_kde now raises an error prompting user to use plot_posterior instead.
 * Rug plots displayed by default for plot_posterior plots.
 * Not included the tests yet.

* Added the test

* Made the suggested changes.

* fixed load_arviz_data import

* Made the suggested changes.

* Added a docstring to my test.

arviz/plots/kdeplot.py

@@ -4,7 +4,8 @@
 from scipy.signal import gaussian, convolve, convolve2d  # pylint: disable=no-name-in-module
 from scipy.sparse import coo_matrix
 from scipy.stats import entropy
-
+import xarray as xr
+from ..data.inference_data import InferenceData
 from ..utils import conditional_jit
 from .plot_utils import _scale_fig_size
 
@@ -146,6 +147,13 @@ def plot_kde(
 
     figsize, *_, xt_labelsize, linewidth, markersize = _scale_fig_size(figsize, textsize, 1, 1)
 
+    if isinstance(values, xr.Dataset):
+        raise ValueError(
+            "Xarray dataset object detected.Use plot_posterior, plot_density, plot_joint"
+            "or plot_pair instead of plot_kde"
+        )
+    if isinstance(values, InferenceData):
+        raise ValueError(" Inference Data object detected. Use plot_posterior instead of plot_kde")
     if values2 is None:
         if plot_kwargs is None:
             plot_kwargs = {}

arviz/plots/posteriorplot.py

@@ -358,6 +358,7 @@ def format_axes():
             fill_kwargs={"alpha": kwargs.pop("fill_alpha", 0)},
             plot_kwargs={"linewidth": linewidth},
             ax=ax,
+            rug=False,
         )
     else:
         if bins is None:

arviz/tests/test_plots.py

@@ -7,8 +7,7 @@
 import pytest
 import pymc3 as pm
 
-
-from ..data import from_dict, from_pymc3
+from ..data import from_dict, from_pymc3, load_arviz_data
 from ..stats import compare, psislw
 from .helpers import eight_schools_params, load_cached_models  # pylint: disable=unused-import
 from ..plots import (
@@ -313,6 +312,18 @@ def test_plot_kde_quantiles(continuous_model, kwargs):
     assert axes
 
 
+def test_plot_kde_inference_data():
+    """
+    Ensure that an exception is raised when plot_kde
+    is used with an inference data or Xarray dataset object.
+    """
+    eight = load_arviz_data("centered_eight")
+    with pytest.raises(ValueError, match="Inference Data"):
+        plot_kde(eight)
+    with pytest.raises(ValueError, match="Xarray"):
+        plot_kde(eight.posterior)
+
+
 def test_plot_khat():
     linewidth = np.random.randn(20000, 10)
     _, khats = psislw(linewidth)