Merge pull request #1441 from vincent-ehrmanntraut/simplified_array_m…

…atrix_mult

Add to_row_matrix and to_column_matrix to Array

Compiler/types.py

@@ -6322,6 +6322,28 @@ def sort(self, n_threads=None, batcher=False, n_bits=None):
             from . import sorting
             sorting.radix_sort(self, self, n_bits=n_bits)
 
+    def to_row_matrix(self):
+        """
+        Returns the array as 1xN matrix.
+
+        Warning: This operation is in-place (without copying data), i.e., all changes to the values of the matrix will also affect the original array.
+        :return: Matrix
+        """
+        assert self.value_type.n_elements() == 1 and \
+               self.value_type.mem_size() == 1
+        return Matrix(1, self.length, self.value_type, address=self.address)
+
+    def to_column_matrix(self):
+        """
+        Returns the array as Nx1 matrix.
+
+        Warning: This operation is in-place (without copying data), i.e., all changes to the values of the matrix will also affect the original array.
+        :return: Matrix
+        """
+        assert self.value_type.n_elements() == 1 and \
+               self.value_type.mem_size() == 1
+        return Matrix(self.length, 1, self.value_type, address=self.address)
+
     def Array(self, size):
         # compatibility with registers
         return Array(size, self.value_type)

Programs/Source/test_dot.mpc

@@ -49,35 +49,32 @@ def test_matrix(expected, actual):
 
                 crash()
 
-break_point()
-def hacky_array_dot_matrix(arr, mat):
-    # Arrays sadly do not have a dot function, therefore the array is converted into a 1 times n Matrix by copying memory addresses.
-    tmp = sint.Matrix(rows=1, columns=len(arr), address=arr.address)
-    result = tmp.dot(mat)
-    return sint.Array(mat.shape[1], result.address)
-
 start_timer(3)
 
-e3 = hacky_array_dot_matrix(a, c)
+e3 = a.to_row_matrix().dot(c).to_array()
 # b[0] = e3[0]
-f3 = hacky_array_dot_matrix(b, d)
+f3 = b.to_row_matrix().dot(d).to_array()
+g3 = c.dot(b.to_column_matrix()).to_array()
 
 stop_timer(3)
 
 e3 = e3.reveal()
 f3 = f3.reveal()
+g3 = g3.reveal()
 
 e3.print_reveal_nested()
 f3.print_reveal_nested()
+g3.print_reveal_nested()
 
 test_array([70, 80, 90], e3)
 test_array([56, 50, 44, 38], f3)
+test_array([10, 28, 46, 64], g3)
 
 start_timer(4)
 
-e4 = hacky_array_dot_matrix(a, c)
+e4 = a.to_row_matrix().dot(c).to_array()
 b[-1] = e4[0]
-f4 = hacky_array_dot_matrix(b, d)
+f4 = b.to_row_matrix().dot(d).to_array()
 
 stop_timer(4)