Solve issue #992 : Integrate point_estimate with rcParam (#994)

* integrated the point_estimate param with rcparam

* added black formatting

* added black formatting

* created new function calculate_point_estimate

* changed the location of _fast_kde function from kdeplot.py to plot_utils.py

* Correct bfmi denominator (#991)

* correct bfmi denominator

* update test_diagnostics.py

* fixed denominator and docs

* changes

* dependency issue solved

* linting changes

* linting changes

* changes

* final changes

* linting correction

* moved _fast_kde_2d function to plot_utils.py

* minor linting changes

Co-authored-by: Nitish Pasricha <pasrichanitish2@gmail.com>

arviz/plots/__init__.py

@@ -9,7 +9,7 @@
 from .forestplot import plot_forest
 from .hpdplot import plot_hpd
 from .jointplot import plot_joint
-from .kdeplot import plot_kde, _fast_kde, _fast_kde_2d
+from .kdeplot import plot_kde
 from .khatplot import plot_khat
 from .loopitplot import plot_loo_pit
 from .mcseplot import plot_mcse
@@ -20,6 +20,7 @@
 from .rankplot import plot_rank
 from .traceplot import plot_trace
 from .violinplot import plot_violin
+from .plot_utils import _fast_kde, _fast_kde_2d
 
 
 __all__ = [

arviz/plots/backends/bokeh/densityplot.py

@@ -5,8 +5,12 @@
 from bokeh.models.annotations import Title
 
 from . import backend_kwarg_defaults, backend_show
-from ...kdeplot import _fast_kde
-from ...plot_utils import _create_axes_grid, make_label
+from ...plot_utils import (
+    make_label,
+    _create_axes_grid,
+    calculate_point_estimate,
+    _fast_kde,
+)
 from ....stats import hpd
 from ....stats.stats_utils import histogram
 
@@ -186,10 +190,7 @@ def _d_helper(
         ax.diamond(xmax, 0, line_color="black", fill_color=color, size=markersize)
 
     if point_estimate is not None:
-        if point_estimate == "mean":
-            est = np.mean(vec)
-        elif point_estimate == "median":
-            est = np.median(vec)
+        est = calculate_point_estimate(point_estimate, vec, bw)
         ax.circle(est, 0, fill_color=color, line_color="black", size=markersize)
 
     _title = Title()

arviz/plots/backends/bokeh/forestplot.py

@@ -12,8 +12,7 @@
 from bokeh.models.tickers import FixedTicker
 
 from . import backend_kwarg_defaults, backend_show
-from ...kdeplot import _fast_kde
-from ...plot_utils import _scale_fig_size, xarray_var_iter, make_label, get_bins
+from ...plot_utils import _scale_fig_size, xarray_var_iter, make_label, get_bins, _fast_kde
 from ....rcparams import rcParams
 from ....stats import hpd
 from ....stats.diagnostics import _ess, _rhat

arviz/plots/backends/bokeh/posteriorplot.py

@@ -6,15 +6,15 @@
 import numpy as np
 from bokeh.layouts import gridplot
 from bokeh.models.annotations import Title
-from scipy.stats import mode
 
 from . import backend_kwarg_defaults, backend_show
-from ...kdeplot import plot_kde, _fast_kde
+from ...kdeplot import plot_kde
 from ...plot_utils import (
     make_label,
     _create_axes_grid,
     format_sig_figs,
     round_num,
+    calculate_point_estimate,
 )
 from ....stats import hpd
 
@@ -189,19 +189,7 @@ def display_rope(max_data):
     def display_point_estimate(max_data):
         if not point_estimate:
             return
-        if point_estimate not in ("mode", "mean", "median"):
-            raise ValueError("Point Estimate should be in ('mode','mean','median')")
-        if point_estimate == "mean":
-            point_value = values.mean()
-        elif point_estimate == "mode":
-            if isinstance(values[0], float):
-                density, lower, upper = _fast_kde(values, bw=bw)
-                x = np.linspace(lower, upper, len(density))
-                point_value = x[np.argmax(density)]
-            else:
-                point_value = mode(values)[0][0]
-        elif point_estimate == "median":
-            point_value = np.median(values)
+        point_value = calculate_point_estimate(point_estimate, values, bw)
         sig_figs = format_sig_figs(point_value, round_to)
         point_text = "{point_estimate}={point_value:.{sig_figs}g}".format(
             point_estimate=point_estimate, point_value=point_value, sig_figs=sig_figs

arviz/plots/backends/matplotlib/densityplot.py

@@ -4,8 +4,12 @@
 
 from . import backend_show
 from ....stats import hpd
-from ...kdeplot import _fast_kde
-from ...plot_utils import _create_axes_grid, make_label
+from ...plot_utils import (
+    make_label,
+    _create_axes_grid,
+    calculate_point_estimate,
+    _fast_kde,
+)
 
 
 def plot_density(
@@ -115,8 +119,9 @@ def _d_helper(
         Size of markers
     credible_interval : float
         Credible intervals. Defaults to 0.94
-    point_estimate : str or None
-        'mean' or 'median'
+    point_estimate : Optional[str]
+        Plot point estimate per variable. Values should be 'mean', 'median', 'mode' or None.
+        Defaults to 'auto' i.e. it falls back to default set in rcParams.
     shade : float
         Alpha blending value for the shaded area under the curve, between 0 (no shade) and 1
         (opaque). Defaults to 0.
@@ -156,10 +161,7 @@ def _d_helper(
         ax.plot(xmax, 0, hpd_markers, color=color, markeredgecolor="k", markersize=markersize)
 
     if point_estimate is not None:
-        if point_estimate == "mean":
-            est = np.mean(vec)
-        elif point_estimate == "median":
-            est = np.median(vec)
+        est = calculate_point_estimate(point_estimate, vec, bw)
         ax.plot(est, 0, "o", color=color, markeredgecolor="k", markersize=markersize)
 
     ax.set_yticks([])

arviz/plots/backends/matplotlib/forestplot.py

@@ -10,8 +10,7 @@
 from ....stats import hpd
 from ....stats.diagnostics import _ess, _rhat
 from ....stats.stats_utils import histogram
-from ...plot_utils import _scale_fig_size, xarray_var_iter, make_label, get_bins
-from ...kdeplot import _fast_kde
+from ...plot_utils import _scale_fig_size, xarray_var_iter, make_label, get_bins, _fast_kde
 from ....utils import conditional_jit
 
 

arviz/plots/backends/matplotlib/loopitplot.py

@@ -3,7 +3,7 @@
 import numpy as np
 
 from . import backend_kwarg_defaults, backend_show
-from ...kdeplot import _fast_kde
+from ...plot_utils import _fast_kde
 from ...hpdplot import plot_hpd
 
 

arviz/plots/backends/matplotlib/posteriorplot.py

@@ -3,16 +3,16 @@
 from numbers import Number
 import matplotlib.pyplot as plt
 import numpy as np
-from scipy.stats import mode
 
 from . import backend_show
 from ....stats import hpd
-from ...kdeplot import plot_kde, _fast_kde
+from ...kdeplot import plot_kde
 from ...plot_utils import (
     make_label,
     _create_axes_grid,
     format_sig_figs,
     round_num,
+    calculate_point_estimate,
 )
 
 
@@ -181,19 +181,7 @@ def display_rope():
     def display_point_estimate():
         if not point_estimate:
             return
-        if point_estimate not in ("mode", "mean", "median"):
-            raise ValueError("Point Estimate should be in ('mode','mean','median')")
-        if point_estimate == "mean":
-            point_value = values.mean()
-        elif point_estimate == "mode":
-            if isinstance(values[0], float):
-                density, lower, upper = _fast_kde(values, bw=bw)
-                x = np.linspace(lower, upper, len(density))
-                point_value = x[np.argmax(density)]
-            else:
-                point_value = mode(values)[0][0]
-        elif point_estimate == "median":
-            point_value = np.median(values)
+        point_value = calculate_point_estimate(point_estimate, values, bw)
         sig_figs = format_sig_figs(point_value, round_to)
         point_text = "{point_estimate}={point_value:.{sig_figs}g}".format(
             point_estimate=point_estimate, point_value=point_value, sig_figs=sig_figs

arviz/plots/backends/matplotlib/ppcplot.py

@@ -4,11 +4,12 @@
 import numpy as np
 
 from . import backend_show
-from ...kdeplot import plot_kde, _fast_kde
+from ...kdeplot import plot_kde
 from ...plot_utils import (
     make_label,
     _create_axes_grid,
     get_bins,
+    _fast_kde,
 )
 from ....stats.stats_utils import histogram
 

arviz/plots/backends/matplotlib/violinplot.py

@@ -5,8 +5,7 @@
 from . import backend_show
 from ....stats import hpd
 from ....stats.stats_utils import histogram
-from ...kdeplot import _fast_kde
-from ...plot_utils import get_bins, make_label, _create_axes_grid
+from ...plot_utils import get_bins, make_label, _create_axes_grid, _fast_kde
 
 
 def plot_violin(

arviz/plots/densityplot.py

@@ -23,7 +23,7 @@ def plot_density(
     data_labels=None,
     var_names=None,
     credible_interval=0.94,
-    point_estimate="mean",
+    point_estimate="auto",
     colors="cycle",
     outline=True,
     hpd_markers="",
@@ -61,8 +61,8 @@ def plot_density(
     credible_interval : float
         Credible intervals. Should be in the interval (0, 1]. Defaults to 0.94.
     point_estimate : Optional[str]
-        Plot point estimate per variable. Values should be 'mean', 'median' or None.
-        Defaults to 'mean'.
+        Plot point estimate per variable. Values should be 'mean', 'median', 'mode' or None.
+        Defaults to 'auto' i.e. it falls back to default set in rcParams.
     colors : Optional[Union[List[str],str]]
         List with valid matplotlib colors, one color per model. Alternative a string can be passed.
         If the string is `cycle`, it will automatically choose a color per model from matplotlib's
@@ -153,12 +153,6 @@ def plot_density(
         datasets = [convert_to_dataset(datum, group=group) for datum in data]
 
     var_names = _var_names(var_names, datasets)
-
-    if point_estimate not in ("mean", "median", None):
-        raise ValueError(
-            "Point estimate should be 'mean'," "median' or None, not {}".format(point_estimate)
-        )
-
     n_data = len(datasets)
 
     if data_labels is None: