sparse iter and _copy_zero

Author: Marie BONBOIRE

src/sage/matrix/matrix_modn_dense_template.pxi

@@ -123,7 +123,7 @@ from sage.structure.proof.proof import get_flag as get_proof_flag
 from sage.structure.richcmp cimport rich_to_bool
 from sage.misc.randstate cimport randstate, current_randstate
 import sage.matrix.matrix_space as matrix_space
-from .args cimport MatrixArgs_init
+from .args cimport SparseEntry, MatrixArgs_init
 
 
 from sage.cpython.string cimport char_to_str
@@ -518,27 +518,49 @@ cdef class Matrix_modn_dense_template(Matrix_dense):
         """
         ma = MatrixArgs_init(parent, entries)
         cdef long i, j
-        it = ma.iter(False)
+        it = ma.iter(convert=False, sparse=True)
         R = ma.base
         p = R.characteristic()
-        for i in range(ma.nrows):
-            v = self._matrix[i]
-            for j in range(ma.ncols):
-                x = next(it)
-                if type(x) is int:
-                    tmp = (<long>x) % p
-                    v[j] = tmp + (tmp<0)*p
-                elif type(x) is IntegerMod_int and (<IntegerMod_int>x)._parent is R:
-                    v[j] = <celement>(<IntegerMod_int>x).ivalue
-                elif type(x) is Integer:
-                    if coerce:
-                        v[j] = mpz_fdiv_ui((<Integer>x).value, p)
-                    else:
-                        v[j] = mpz_get_ui((<Integer>x).value)
-                elif coerce:
-                    v[j] = R(x)
+        
+        for t in it:
+            se = <SparseEntry>t
+            x = se.entry
+            v = self._matrix[se.i]
+            if type(x) is int:
+                tmp = (<long>x) % p
+                v[se.j] = tmp + (tmp<0)*p
+            elif type(x) is IntegerMod_int and (<IntegerMod_int>x)._parent is R:
+                v[se.j] = <celement>(<IntegerMod_int>x).ivalue
+            elif type(x) is Integer:
+                if coerce:
+                    v[se.j] = mpz_fdiv_ui((<Integer>x).value, p)
                 else:
                     v[j] = <celement>x
+                    v[se.j] = mpz_get_ui((<Integer>x).value)
+            elif coerce:
+                v[se.j] = R(x)
+            else:
+                v[se.j] = <celement>x
+
+	
+        #for i in range(ma.nrows):
+        #    v = self._matrix[i]
+        #    for j in range(ma.ncols):
+        #        x = next(it)
+        #        if type(x) is int:
+        #            tmp = (<long>x) % p
+        #            v[j] = tmp + (tmp<0)*p
+        #        elif type(x) is IntegerMod_int and (<IntegerMod_int>x)._parent is R:
+        #            v[j] = <celement>(<IntegerMod_int>x).ivalue
+        #        elif type(x) is Integer:
+        #            if coerce:
+        #                v[j] = mpz_fdiv_ui((<Integer>x).value, p)
+        #            else:
+        #                v[j] = mpz_get_ui((<Integer>x).value)
+        #        elif coerce:
+        #            v[j] = R(x)
+        #        else:
+        #            v[j] = <celement>x
 
     cdef long _hash_(self) except -1:
         """

src/sage/matrix/matrix_space.py

@@ -1804,7 +1804,12 @@ def identity_matrix(self):
         """
         if self.__nrows != self.__ncols:
             raise TypeError("identity matrix must be square")
-        A = self.zero_matrix().__copy__()
+        
+        if self._copy_zero:
+            A = self.zero_matrix().__copy__()
+        else:
+            A = self.matrix()
+
         for i in range(self.__nrows):
             A[i, i] = 1
         A.set_immutable()
@@ -1863,7 +1868,12 @@ def diagonal_matrix(self, entries):
             raise TypeError("diagonal matrix must be square")
         if self.__nrows < len(entries):
             raise ValueError('number of diagonal matrix entries (%s) exceeds the matrix size (%s)' % (len(entries), self.__nrows))
-        A = self.zero_matrix().__copy__()
+        
+        if self._copy_zero:
+            A = self.zero_matrix().__copy__()
+        else:
+            A = self.matrix()
+
         for i in range(len(entries)):
             A[i, i] = entries[i]
         return A