1 files changed, 104 insertions, 0 deletions
diff --git a/histogram.py b/histogram.py
new file mode 100644
index 0000000..ca67839
--- /dev/null
+++ b/histogram.py
@@ -0,0 +1,104 @@
+#!/usr/bin/env python3
+
+import math
+from numbers import Number
+from typing import Generic, Iterable, List, Optional, Tuple, TypeVar
+
+from math_utils import RunningMedian
+from text_utils import bar_graph
+
+
+T = TypeVar("T", bound=Number)
+
+
+class SimpleHistogram(Generic[T]):
+
+    # Useful in defining wide open bottom/top bucket bounds:
+    POSITIVE_INFINITY = math.inf
+    NEGATIVE_INFINITY = -math.inf
+
+    def __init__(self, buckets: List[Tuple[T, T]]):
+        self.buckets = {}
+        for start_end in buckets:
+            if self._get_bucket(start_end[0]) is not None:
+                raise Exception("Buckets overlap?!")
+            self.buckets[start_end] = 0
+        self.sigma = 0
+        self.median = RunningMedian()
+        self.maximum = None
+        self.minimum = None
+        self.count = 0
+
+    @staticmethod
+    def n_evenly_spaced_buckets(
+            min_bound: T,
+            max_bound: T,
+            n: int,
+    ) -> List[Tuple[T, T]]:
+        ret = []
+        stride = int((max_bound - min_bound) / n)
+        if stride <= 0:
+            raise Exception("Min must be < Max")
+        for bucket_start in range(min_bound, max_bound, stride):
+            ret.append((bucket_start, bucket_start + stride))
+        return ret
+
+    def _get_bucket(self, item: T) -> Optional[Tuple[T, T]]:
+        for start_end in self.buckets:
+            if start_end[0] <= item < start_end[1]:
+                return start_end
+        return None
+
+    def add_item(self, item: T) -> bool:
+        bucket = self._get_bucket(item)
+        if bucket is None:
+            return False
+        self.count += 1
+        self.buckets[bucket] += 1
+        self.sigma += item
+        self.median.add_number(item)
+        if self.maximum is None or item > self.maximum:
+            self.maximum = item
+        if self.minimum is None or item < self.minimum:
+            self.minimum = item
+        return True
+
+    def add_items(self, lst: Iterable[T]) -> bool:
+        all_true = True
+        for item in lst:
+            all_true = all_true and self.add_item(item)
+        return all_true
+
+    def __repr__(self) -> str:
+        max_population: Optional[int] = None
+        for bucket in self.buckets:
+            pop = self.buckets[bucket]
+            if pop > 0:
+                last_bucket_start = bucket[0]
+            if max_population is None or pop > max_population:
+                max_population = pop
+        txt = ""
+        if max_population is None:
+            return txt
+
+        for bucket in sorted(self.buckets, key=lambda x : x[0]):
+            pop = self.buckets[bucket]
+            start = bucket[0]
+            end = bucket[1]
+            bar = bar_graph(
+                (pop / max_population),
+                include_text = False,
+                width = 70,
+                left_end = "",
+                right_end = "")
+            label = f'{start}..{end}'
+            txt += f'{label:12}: ' + bar + f"({pop}) ({len(bar)})\n"
+            if start == last_bucket_start:
+                break
+
+        txt = txt + f'''{self.count} item(s)
+{self.maximum} max
+{self.minimum} min
+{self.sigma/self.count:.3f} mean
+{self.median.get_median()} median'''
+        return txt