[Numpy-svn] r8382 - trunk/numpy/lib

[numpy-svn at scipy.org]

Author: charris
Date: 2010-05-04 21:50:00 -0500 (Tue, 04 May 2010)
New Revision: 8382

Modified:
   trunk/numpy/lib/polynomial.py
Log:
BUG: Make polyder return a poly1d for the zeroeth order derivative when
the input is a poly1d. Fixes ticket #1249.

Modified: trunk/numpy/lib/polynomial.py
===================================================================
--- trunk/numpy/lib/polynomial.py	2010-05-04 06:24:07 UTC (rev 8381)
+++ trunk/numpy/lib/polynomial.py	2010-05-05 02:50:00 UTC (rev 8382)
@@ -378,19 +378,20 @@
 
     """
     m = int(m)
+    if m < 0:
+        raise ValueError, "Order of derivative must be positive (see polyint)"
+
     truepoly = isinstance(p, poly1d)
     p = NX.asarray(p)
-    n = len(p)-1
+    n = len(p) - 1
     y = p[:-1] * NX.arange(n, 0, -1)
-    if m < 0:
-        raise ValueError, "Order of derivative must be positive (see polyint)"
     if m == 0:
-        return p
+        val = p
     else:
-        val = polyder(y, m-1)
-        if truepoly:
-            val = poly1d(val)
-        return val
+        val = polyder(y, m - 1)
+    if truepoly:
+        val = poly1d(val)
+    return val
 
 def polyfit(x, y, deg, rcond=None, full=False):
     """