1 files changed, 29 insertions, 18 deletions
diff --git a/numpy/polynomial/chebyshev.py b/numpy/polynomial/chebyshev.py
index 662f664a9..2b6d7b4bb 100644
--- a/numpy/polynomial/chebyshev.py
+++ b/numpy/polynomial/chebyshev.py
@@ -846,25 +846,29 @@ def chebder(cs, m=1, scl=1) :
     array([ 12.,  96.])
 
     """
-    # cs is a trimmed copy
-    [cs] = pu.as_series([cs])
-    if m < 0 :
-        raise ValueError, "The order of derivation must be positive"
+    cnt = int(m)
+
+    if cnt != m:
+        raise ValueError, "The order of derivation must be integer"
+    if cnt < 0 :
+        raise ValueError, "The order of derivation must be non-negative"
     if not np.isscalar(scl) :
         raise ValueError, "The scl parameter must be a scalar"
 
-    if m == 0 :
+    # cs is a trimmed copy
+    [cs] = pu.as_series([cs])
+    if cnt == 0:
         return cs
-    elif m >= len(cs) :
+    elif cnt >= len(cs):
         return cs[:1]*0
     else :
         zs = _cseries_to_zseries(cs)
-        for i in range(m) :
+        for i in range(cnt):
             zs = _zseries_der(zs)*scl
         return _zseries_to_cseries(zs)
 
 
-def chebint(cs, m=1, k=[], lbnd=0, scl=1) :
+def chebint(cs, m=1, k=[], lbnd=0, scl=1):
     """
     Integrate a Chebyshev series.
 
@@ -941,11 +945,15 @@ def chebint(cs, m=1, k=[], lbnd=0, scl=1) :
     array([-1.,  1., -1., -1.])
 
     """
+    cnt = int(m)
     if np.isscalar(k) :
         k = [k]
-    if m < 1 :
-        raise ValueError, "The order of integration must be positive"
-    if len(k) > m :
+
+    if cnt != m:
+        raise ValueError, "The order of integration must be integer"
+    if cnt < 0 :
+        raise ValueError, "The order of integration must be non-negative"
+    if len(k) > cnt :
         raise ValueError, "Too many integration constants"
     if not np.isscalar(lbnd) :
         raise ValueError, "The lbnd parameter must be a scalar"
@@ -954,13 +962,16 @@ def chebint(cs, m=1, k=[], lbnd=0, scl=1) :
 
     # cs is a trimmed copy
     [cs] = pu.as_series([cs])
-    k = list(k) + [0]*(m - len(k))
-    for i in range(m) :
-        zs = _cseries_to_zseries(cs)*scl
-        zs = _zseries_int(zs)
-        cs = _zseries_to_cseries(zs)
-        cs[0] += k[i] - chebval(lbnd, cs)
-    return cs
+    if cnt == 0:
+        return cs
+    else:
+        k = list(k) + [0]*(cnt - len(k))
+        for i in range(cnt) :
+            zs = _cseries_to_zseries(cs)*scl
+            zs = _zseries_int(zs)
+            cs = _zseries_to_cseries(zs)
+            cs[0] += k[i] - chebval(lbnd, cs)
+        return cs
 
 def chebval(x, cs):
     """Evaluate a Chebyshev series.