Adding median statistics

.pre-commit-config.yaml

@@ -14,11 +14,11 @@ repos:
           - --unsafe
       - id: trailing-whitespace
   - repo: https://github.com/psf/black
-    rev: 23.9.1
+    rev: 23.10.0
     hooks:
       - id: black
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.0.292
+    rev: v0.1.0
     hooks:
       - id: ruff
         args: ["--fix"]

src/chainconsumer/analysis.py

@@ -53,6 +53,7 @@ def __init__(self, parent: ChainConsumer):
             SummaryStatistic.MEAN: self.get_parameter_summary_mean,
             SummaryStatistic.CUMULATIVE: self.get_parameter_summary_cumulative,
             SummaryStatistic.MAX_CENTRAL: self.get_parameter_summary_max_central,
+            SummaryStatistic.MEDIAN: self.get_parameter_summary_median,
         }
 
     def get_latex_table(
@@ -465,6 +466,12 @@ def get_parameter_summary_max_central(self, chain, parameter):
 
         return Bound(lower=xvals[0], center=x, upper=xvals[1])
 
+    def get_parameter_summary_median(self, chain, parameter):
+        vals = 100 * np.array([0.5 - 0.5 * chain.summary_area, 0.5, 0.5 + 0.5 * chain.summary_area])
+        xvals = np.percentile(chain.get_data(parameter), vals)
+
+        return Bound(lower=xvals[0], center=xvals[1], upper=xvals[2])
+
 
 if __name__ == "__main__":
     from .chainconsumer import ChainConsumer

src/chainconsumer/statistics.py

@@ -18,3 +18,7 @@ class SummaryStatistic(Enum):
     MEAN = "mean"
     """As per the cumulative method, except the central value is placed in the midpoint between
     the upper and lower boundary. Not recommended, but was requested."""
+
+    MEDIAN = "median"
+    """The central point is set to median of the pdf, and the upper and the upper
+    and lower bounds are determined by the percentiles of the pdf."""