Remove code from Stack Overflow and wasteful loop

Stack Overflow content is CC-BY-SA licensed,
which this package is not supposed to be.  This snippet may be
too small to be copyrightable, but removing it to be safe.

Author: Rebecca N. Palmer <rebecca_palmer@zoho.com>
Forwarded: no

Gbp-Pq: Name remove_ccbysa_snippet.patch

diff --git a/statsmodels/examples/ex_generic_mle_tdist.py b/statsmodels/examples/ex_generic_mle_tdist.py
index 4959b811baeebae99dbc516b77c26240408246be..e621c72ea3396b95dbf7c6f75866e6cc70fbce54 100644 (file)
--- a/statsmodels/examples/ex_generic_mle_tdist.py
+++ b/statsmodels/examples/ex_generic_mle_tdist.py
@@ -198,6 +198,9 @@ class MyPareto(GenericLikelihoodModel):
         this does not trim lower values during ks optimization
 
         '''
+        # all 3 of these are based on
+        # https://stackoverflow.com/questions/3242326/fitting-a-pareto-distribution-with-python-scipy
+        # validly licensed because the same person added it there and here
         rvs = self.endog
         rvsmin = rvs.min()
         fixdf = np.nan * np.ones(3)

diff --git a/statsmodels/graphics/regressionplots.py b/statsmodels/graphics/regressionplots.py
index 95962d61768777d5aca411c80c6ade0661cbaca9..dfa21c792f75cd7706755f0799293d61b3c49ac4 100644 (file)
--- a/statsmodels/graphics/regressionplots.py
+++ b/statsmodels/graphics/regressionplots.py
@@ -434,11 +434,12 @@ def plot_partregress(endog, exog_i, exog_others, data=None,
     ax.set_ylabel("e(%s | X)" % y_axis_endog_name)
     ax.set_title('Partial Regression Plot', **title_kwargs)
 
-    # NOTE: if we want to get super fancy, we could annotate if a point is
-    # clicked using this widget
+    # NOTE: it is possible to annotate if a point is clicked using
     # http://stackoverflow.com/questions/4652439/
     # is-there-a-matplotlib-equivalent-of-matlabs-datacursormode/
     # 4674445#4674445
+    # but for licensing reasons this is _not_ to be directly copied
+    # into statsmodels itself
     if obs_labels is True:
         if data is not None:
             obs_labels = data.index

diff --git a/statsmodels/tools/sequences.py b/statsmodels/tools/sequences.py
index de409ee27ea4081936f345d9665d5d20f923002a..80ec9940ebe5b365d032c43a0d6446d105c44c7f 100644 (file)
--- a/statsmodels/tools/sequences.py
+++ b/statsmodels/tools/sequences.py
@@ -61,24 +61,22 @@ def primes_from_2_to(n):
     Parameters
     ----------
     n : int
-        Sup bound with ``n >= 6``.
+        Upper limit (exclusive).
 
     Returns
     -------
     primes : list(int)
         Primes in ``2 <= p < n``.
-
-    References
-    ----------
-    [1] `StackOverflow <https://stackoverflow.com/questions/2068372>`_.
     """
-    sieve = np.ones(n // 3 + (n % 6 == 2), dtype=bool)
-    for i in range(1, int(n ** 0.5) // 3 + 1):
-        if sieve[i]:
-            k = 3 * i + 1 | 1
-            sieve[k * k // 3::2 * k] = False
-            sieve[k * (k - 2 * (i & 1) + 4) // 3::2 * k] = False
-    return np.r_[2, 3, ((3 * np.nonzero(sieve)[0][1:] + 1) | 1)]
+    isprime = np.ones((n - 2,))  # 2...n-1, so indices offset by 2 from values
+    endidx = int(np.sqrt(n)) - 1
+    nextprime = 2
+    while True:
+        isprime[nextprime * nextprime - 2::nextprime] = 0
+        nextps = np.nonzero(isprime[nextprime - 1:endidx])[0]
+        if len(nextps) == 0:
+            return np.nonzero(isprime)[0] + 2
+        nextprime = nextprime + nextps[0] + 1
 
 
 def n_primes(n):
@@ -109,12 +107,13 @@ def n_primes(n):
               953, 967, 971, 977, 983, 991, 997][:n]
 
     if len(primes) < n:
-        big_number = 10
-        while 'Not enought primes':
+        # this should always be enough - Rosser (1941)
+        big_number = int(n * (np.log(n) + np.log(np.log(n))))
+        while True:  # not enough primes
             primes = primes_from_2_to(big_number)[:n]
             if len(primes) == n:
                 break
-            big_number += 1000
+            big_number = int(big_number * 1.5)
 
     return primes