Added feature / new keyword to round any numbers in title: title_round

src/corner/arviz_corner.py

@@ -96,6 +96,7 @@ def arviz_corner(
     titles=None,
     show_titles=False,
     title_fmt=".2f",
+    title_round=None,
     title_kwargs=None,
     truths=None,
     truth_color="#4682b4",
@@ -188,6 +189,7 @@ def arviz_corner(
         titles=titles,
         show_titles=show_titles,
         title_fmt=title_fmt,
+        title_round=title_round,
         title_kwargs=title_kwargs,
         truths=truths,
         truth_color=truth_color,

src/corner/core.py

@@ -44,6 +44,7 @@ def corner_impl(
     titles=None,
     show_titles=False,
     title_fmt=".2f",
+    title_round=None,
     title_kwargs=None,
     truths=None,
     truth_color="#4682b4",
@@ -120,6 +121,14 @@ def corner_impl(
             len(title_fmt) == K
         ), "'title_fmt' should contain as many elements as data dimensions"
 
+    # Make title_round into a list if necessary, otherwise check length
+    if isinstance(title_round, int):
+        title_round = [title_round] * K
+    elif title_round is not None:
+        assert (
+            len(title_fmt) == K
+        ), "'title_round' should contain as many elements as data dimensions"
+
     # Make axes_scale into a list if necessary, otherwise check length
     if isinstance(axes_scale, str):
         axes_scale = [axes_scale] * K
@@ -270,9 +279,22 @@ def corner_impl(
                 )
                 q_m, q_p = q_mid - q_lo, q_hi - q_mid
 
+                # Round the titles if needed
+                if title_round is not None and title_round[i] is not None:
+                    q_m, q_mid, q_p = (
+                        round(q_m, title_round[i]),
+                        round(q_mid, title_round[i]),
+                        round(q_p, title_round[i]),
+                    )
+
                 # Format the quantile display.
                 fmt = "{{0:{0}}}".format(title_fmt[i]).format
                 title = r"${{{0}}}_{{-{1}}}^{{+{2}}}$"
+
+                # Check for symmetric errorbars
+                if fmt(q_m) == fmt(q_p):
+                    title = r"${{{0}}}\pm{{{1}}}$"
+
                 title = title.format(fmt(q_mid), fmt(q_m), fmt(q_p))
 
                 # Add in the column name if it's given.

src/corner/corner.py

@@ -32,6 +32,7 @@ def corner(
     show_titles=False,
     title_quantiles=None,
     title_fmt=".2f",
+    title_round=None,
     title_kwargs=None,
     truths=None,
     truth_color="#4682b4",
@@ -149,10 +150,19 @@ def corner(
         quantiles is `None`, in which case it defaults to [0.16,0.5,0.84]
 
     title_fmt : string or iterable (ndim,)
-        The format string for the quantiles given in titles for eachimension.
+        The format string for the quantiles given in titles for each dimension.
         If you explicitly set ``show_titles=True`` and ``title_fmt=None``,
         the labels will be shown as the titles. (default: ``.2f``)
 
+    title_round : int or iterable (ndim,)
+        Specifies how many digits to round to after the decimal point for each
+        dimension. Use negative values for rounding to left of decimal point.
+        Uses python `round() function for rounding.
+        If rounding right of decimal point, use ``title_fmt`` instead
+        since `round()` can give unexpected behavior for floats.
+        Specify `None` for any dimension to not be formatted with `round()`.
+        (default: `None`)
+
     title_kwargs : dict
         Any extra keyword arguments to send to the `set_title` command.
 
@@ -261,6 +271,7 @@ def corner(
             show_titles=show_titles,
             title_quantiles=title_quantiles,
             title_fmt=title_fmt,
+            title_round=title_round,
             title_kwargs=title_kwargs,
             truths=truths,
             truth_color=truth_color,
@@ -293,6 +304,7 @@ def corner(
         show_titles=show_titles,
         title_quantiles=title_quantiles,
         title_fmt=title_fmt,
+        title_round=title_round,
         title_kwargs=title_kwargs,
         truths=truths,
         truth_color=truth_color,