Ticket #10951: trac_10951.patch

sage/libs/libecm.pyx

@@ -8 +8 @@
 
 AUTHOR:
     Robert L Miller (2008-01-21) -- library interface (clone of ecmfactor.c)
+    Paul Zimmermann (2011-05-22) -- added input/output of sigma
 
 EXAMPLE:
 
     sage: import sage.libs.libecm
     sage: from sage.libs.libecm import ecmfactor
     sage: result = ecmfactor(999, 0.00)
-    sage: result in [(True, 27), (True, 37), (True, 999)]
+    sage: result[0] == True and result[1] in [27, 37, 999]
     True
     sage: result = ecmfactor(999, 0.00, verbose=True)
     Performing one curve with B1=0
     Found factor in step 1: ...
-    sage: result in [(True, 27), (True, 37), (True, 999)]
+    sage: result[0] == True and result[1] in [27, 37, 999]
     True
+    sage: ecmfactor(2^128+1,1000,sigma=227140902)
+    (True, 5704689200685129054721, 227140902)
 
 """
 
@@ -30 +33 @@
 
 cdef extern from "ecm.h":
     ctypedef struct __ecm_param_struct:
-        pass
+        int method
+        mpz_t x
+        mpz_t sigma
     ctypedef __ecm_param_struct ecm_params[1]
     int ecm_factor (mpz_t, mpz_t, double, ecm_params)
+    void ecm_init (ecm_params)
+    void ecm_clear (ecm_params)
     int ECM_NO_FACTOR_FOUND
 
-def ecmfactor(number, py_B1, verbose=False):
+def ecmfactor(number, py_B1, verbose=False, sigma=0):
     cdef mpz_t n, f
     cdef int res
     cdef double B1
-    cdef Integer sage_int_f, sage_int_number
+    cdef Integer sage_int_f, sage_int_number, sage_int_sigma
+    cdef ecm_params q
     
     sage_int_f = Integer(0)
     sage_int_number = Integer(number)
+    sage_int_sigma = Integer(sigma)
     B1 = py_B1
 
     mpz_init(n)
     mpz_set(n, sage_int_number.value)
     mpz_init(f) # For potential factor
+    ecm_init(q)
+    mpz_set(q.sigma,sage_int_sigma.value)
 
     if verbose:
         print "Performing one curve with B1=%1.0f"%B1
 
-    res = ecm_factor(f, n, B1, NULL)
+    res = ecm_factor(f, n, B1, q)
 
     if res > 0:
         mpz_set(sage_int_f.value, f)
+        mpz_set(sage_int_sigma.value, q.sigma)
 
     mpz_clear(f)
     mpz_clear(n)
+    ecm_clear(q)
 
     if res > 0:
         if verbose:
             print "Found factor in step %d: %d"%(res,sage_int_f)
-        return (True, sage_int_f)
+        return (True, sage_int_f, sage_int_sigma)
     elif res == ECM_NO_FACTOR_FOUND:
         if verbose:
             print "Found no factor."