Unit Test:void matrix::fill_out(const double x) (#2014)

Author: KCJ2000

source/module_base/test/matrix_test.cpp

@@ -18,6 +18,7 @@
  *      - operator "*=", "+=", "-="
  *      - function trace_on
  *      - function zero_out
+ *      - function fill_out
  *      - function max/min/absmax
  *      - function norm
  *      - function print (not called in abacus, no need to test)
@@ -337,3 +338,16 @@ TEST_F(matrixTest,Alloc)
 	output = testing::internal::GetCapturedStdout();
 	EXPECT_THAT(output,testing::HasSubstr("Allocation error for Matrix"));
 }
+
+TEST_F(matrixTest,Fillout)
+{
+    double k=2.4;
+    m33a.fill_out(k);
+    for (int i=0;i<m33a.nr;++i)
+    {
+        for (int j=0;j<m33a.nc;++j)
+        {
+            EXPECT_DOUBLE_EQ(m33a(i,j),k);
+        }
+    }
+}