added year as an allowable time unit for display

[p2pool.git] / p2pool / util / math.py

diff --git a/p2pool/util/math.py b/p2pool/util/math.py
index 614a0f2..04ed3ff 100644 (file)
--- a/p2pool/util/math.py
+++ b/p2pool/util/math.py
@@ -3,6 +3,7 @@ from __future__ import absolute_import, division
 import __builtin__
 import math
 import random
+import time
 
 def median(x, use_float=True):
     # there exist better algorithms...
@@ -44,6 +45,8 @@ def clip(x, (low, high)):
     else:
         return x
 
+add_to_range = lambda x, (low, high): (min(low, x), max(high, x))
+
 def nth(i, n=0):
     i = iter(i)
     for _ in xrange(n):
@@ -57,12 +60,17 @@ def geometric(p):
         return 1
     return int(math.log1p(-random.random()) / math.log1p(-p)) + 1
 
-def add_dicts(*dicts):
-    res = {}
-    for d in dicts:
-        for k, v in d.iteritems():
-            res[k] = res.get(k, 0) + v
-    return dict((k, v) for k, v in res.iteritems() if v)
+def add_dicts_ext(add_func=lambda a, b: a+b, zero=0):
+    def add_dicts(*dicts):
+        res = {}
+        for d in dicts:
+            for k, v in d.iteritems():
+                res[k] = add_func(res.get(k, zero), v)
+        return dict((k, v) for k, v in res.iteritems() if v != zero)
+    return add_dicts
+add_dicts = add_dicts_ext()
+
+mult_dict = lambda c, x: dict((k, c*v) for k, v in x.iteritems())
 
 def format(x):
     prefixes = 'kMGTPEZY'
@@ -73,6 +81,12 @@ def format(x):
     s = '' if count == 0 else prefixes[count - 1]
     return '%i' % (x,) + s
 
+def format_dt(dt):
+    for value, name in [(365.2425*60*60*24, 'years'), (60*60*24, 'days'), (60*60, 'hours'), (60, 'minutes'), (1, 'seconds')]:
+        if dt > value:
+            break
+    return '%.01f %s' % (dt/value, name)
+
 perfect_round = lambda x: int(x + random.random())
 
 def erf(x):
@@ -108,43 +122,18 @@ def find_root(y_over_dy, start, steps=10, bounds=(None, None)):
 def ierf(z):
     return find_root(lambda x: (erf(x) - z)/(2*math.e**(-x**2)/math.sqrt(math.pi)), 0)
 
-try:
-    from scipy import special
-except ImportError:
-    print 'Install SciPy for more accurate confidence intervals!'
-    def binomial_conf_interval(x, n, conf=0.95):
-        assert 0 <= x <= n and 0 <= conf < 1
-        if n == 0:
-            left = random.random()*(1 - conf)
-        # approximate - Wilson score interval
-        z = math.sqrt(2)*ierf(conf)
-        p = x/n
-        topa = p + z**2/2/n
-        topb = z * math.sqrt(p*(1-p)/n + z**2/4/n**2)
-        bottom = 1 + z**2/n
-        return (topa - topb)/bottom, (topa + topb)/bottom
-else:
-    def binomial_conf_interval(x, n, conf=0.95):
-        assert 0 <= x <= n and 0 <= conf < 1
-        if n == 0:
-            left = random.random()*(1 - conf)
-            return left, left + conf
-        b = special.beta(x+1, n-x+1)
-        def f(left_a):
-            left, right = max(1e-8, special.betaincinv(x+1, n-x+1, left_a)), min(1-1e-8, special.betaincinv(x+1, n-x+1, left_a + conf))
-            top = right**(x+1) * (1-right)**(n-x+1) * left*(1-left) - left**(x+1) * (1-left)**(n-x+1) * right * (1-right)
-            bottom = (x - n*right)*left*(1-left) - (x - n*left)*right*(1-right)
-            return top/bottom/b
-        left_a = find_root(f, (1-conf)/2, bounds=(0, 1-conf))
-        return special.betaincinv(x+1, n-x+1, left_a), special.betaincinv(x+1, n-x+1, left_a + conf)
-
-def binomial_conf_center_radius(x, n, conf=0.95):
+def binomial_conf_interval(x, n, conf=0.95):
     assert 0 <= x <= n and 0 <= conf < 1
-    left, right = binomial_conf_interval(x, n, conf)
     if n == 0:
-        return (left+right)/2, (right-left)/2
+        left = random.random()*(1 - conf)
+        return left, left + conf
+    # approximate - Wilson score interval
+    z = math.sqrt(2)*ierf(conf)
     p = x/n
-    return p, max(p - left, right - p)
+    topa = p + z**2/2/n
+    topb = z * math.sqrt(p*(1-p)/n + z**2/4/n**2)
+    bottom = 1 + z**2/n
+    return [clip(x, (0, 1)) for x in add_to_range(x/n, [(topa - topb)/bottom, (topa + topb)/bottom])]
 
 minmax = lambda x: (min(x), max(x))
 
@@ -152,7 +141,7 @@ def format_binomial_conf(x, n, conf=0.95, f=lambda x: x):
     if n == 0:
         return '???'
     left, right = minmax(map(f, binomial_conf_interval(x, n, conf)))
-    return '~%.1f%% (%.f-%.f%%)' % (100*f(x/n), 100*left-1/2, 100*right+1/2)
+    return '~%.1f%% (%.f-%.f%%)' % (100*f(x/n), math.floor(100*left), math.ceil(100*right))
 
 def reversed(x):
     try:
@@ -190,7 +179,7 @@ def natural_to_string(n, alphabet=None):
     if n < 0:
         raise TypeError('n must be a natural')
     if alphabet is None:
-        s = '%x' % (n,)
+        s = ('%x' % (n,)).lstrip('0')
         if len(s) % 2:
             s = '0' + s
         return s.decode('hex')
@@ -212,9 +201,32 @@ def string_to_natural(s, alphabet=None):
         assert not s.startswith(alphabet[0])
         return sum(alphabet.index(char) * len(alphabet)**i for i, char in enumerate(reversed(s)))
 
-if __name__ == '__main__':
-    import random
-    a = 1
-    while True:
-        print a, format(a) + 'H/s'
-        a = a * random.randrange(2, 5)
+class RateMonitor(object):
+    def __init__(self, max_lookback_time):
+        self.max_lookback_time = max_lookback_time
+        
+        self.datums = []
+        self.first_timestamp = None
+    
+    def _prune(self):
+        start_time = time.time() - self.max_lookback_time
+        for i, (ts, datum) in enumerate(self.datums):
+            if ts > start_time:
+                self.datums[:] = self.datums[i:]
+                return
+    
+    def get_datums_in_last(self, dt=None):
+        if dt is None:
+            dt = self.max_lookback_time
+        assert dt <= self.max_lookback_time
+        self._prune()
+        now = time.time()
+        return [datum for ts, datum in self.datums if ts > now - dt], min(dt, now - self.first_timestamp) if self.first_timestamp is not None else 0
+    
+    def add_datum(self, datum):
+        self._prune()
+        t = time.time()
+        if self.first_timestamp is None:
+            self.first_timestamp = t
+        else:
+            self.datums.append((t, datum))