add unit tests for library interface function lammps_extract_pair() and python equivalent

unittest/c-library/test_library_properties.cpp

@@ -418,7 +418,7 @@ TEST_F(LibraryProperties, global)
     EXPECT_EQ(map_style, Atom::MAP_ARRAY);
     EXPECT_NE(sametag, nullptr);
 
-    auto *tags        = (tagint *)lammps_extract_atom(lmp, "id");
+    auto *tags              = (tagint *)lammps_extract_atom(lmp, "id");
     const tagint sometags[] = {1, 5, 10, 15, 20};
     for (const auto &sometag : sometags) {
         int idx = lammps_map_atom(lmp, (const void *)&sometag);
@@ -467,6 +467,54 @@ TEST_F(LibraryProperties, global)
     EXPECT_EQ(map_style, Atom::MAP_ARRAY);
 };
 
+TEST_F(LibraryProperties, pair1)
+{
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lammps_command(lmp, "region box block 0 1 0 1 0 1");
+    lammps_command(lmp, "create_box 3 box");
+    lammps_command(lmp, "mass * 1.0");
+    lammps_command(lmp, "pair_style lj/cut 3.0");
+    lammps_command(lmp, "pair_coeff 1 1 1.0 1.0");
+    lammps_command(lmp, "pair_coeff 2 2 1.5 2.0");
+    lammps_command(lmp, "pair_coeff 3 3 1.0 3.0");
+    lammps_command(lmp, "run 0 post no");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    EXPECT_EQ(lammps_extract_pair_dimension(lmp, "epsilon"), 2);
+    EXPECT_EQ(lammps_extract_pair_dimension(lmp, "sigma"), 2);
+    EXPECT_EQ(lammps_extract_pair_dimension(lmp, "cut_coul"), -1);
+    auto **sigma = (double **)lammps_extract_pair(lmp, "sigma");
+    EXPECT_DOUBLE_EQ(sigma[1][1], 1.0);
+    EXPECT_DOUBLE_EQ(sigma[2][2], 2.0);
+    EXPECT_DOUBLE_EQ(sigma[3][3], 3.0);
+    EXPECT_DOUBLE_EQ(sigma[1][2], sqrt(2.0));
+};
+
+TEST_F(LibraryProperties, pair2)
+{
+    if (!lammps_has_style(lmp, "pair", "coul/streitz")) GTEST_SKIP();
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lammps_command(lmp, "units metal");
+    lammps_command(lmp, "atom_style charge");
+    lammps_command(lmp, "region box block 0 1 0 1 0 1");
+    lammps_command(lmp, "create_box 2 box");
+    lammps_command(lmp, "mass * 1.0");
+    lammps_command(lmp, "pair_style coul/streitz 12.0 wolf 0.31");
+    lammps_command(lmp, "pair_coeff * * AlO.streitz Al O");
+    lammps_command(lmp, "run 0 post no");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    EXPECT_EQ(lammps_extract_pair_dimension(lmp, "chi"), 1);
+    EXPECT_EQ(lammps_extract_pair_dimension(lmp, "scale"), 2);
+    EXPECT_EQ(lammps_extract_pair_dimension(lmp, "cut_coul"), 0);
+    EXPECT_DOUBLE_EQ(*((double *)lammps_extract_pair(lmp, "cut_coul")), 12.0);
+    auto *chi = (double *)lammps_extract_pair(lmp, "chi");
+    EXPECT_DOUBLE_EQ(chi[1], 0.0);
+    EXPECT_FLOAT_EQ(chi[2], 5.484763);
+    auto **scale = (double **)lammps_extract_pair(lmp, "scale");
+    EXPECT_DOUBLE_EQ(scale[1][1], 1.0);
+    EXPECT_DOUBLE_EQ(scale[1][2], 1.0);
+    EXPECT_DOUBLE_EQ(scale[2][2], 1.0);
+};
+
 TEST_F(LibraryProperties, neighlist)
 {
     if (!lammps_has_style(lmp, "pair", "sw")) GTEST_SKIP();

unittest/python/python-commands.py

@@ -3,6 +3,7 @@ import sys,os,unittest,ctypes
 from lammps import lammps, LMP_VAR_ATOM, LMP_STYLE_GLOBAL, LMP_STYLE_LOCAL
 from lammps import LMP_TYPE_VECTOR, LMP_SIZE_VECTOR, LMP_SIZE_ROWS, LMP_SIZE_COLS
 from lammps import LAMMPS_DOUBLE_2D, LAMMPS_AUTODETECT
+import math
 
 has_manybody=False
 try:
@@ -15,6 +16,17 @@ try:
 except:
     pass
 
+has_streitz=False
+try:
+    machine=None
+    if 'LAMMPS_MACHINE_NAME' in os.environ:
+        machine=os.environ['LAMMPS_MACHINE_NAME']
+    lmp=lammps(name=machine)
+    has_streitz = lmp.has_style("pair","coul/streitz")
+    lmp.close()
+except:
+    pass
+
 class PythonCommand(unittest.TestCase):
 
     def setUp(self):
@@ -666,6 +678,49 @@ create_atoms 1 single &
         self.lmp.command("balance 0.1 rcb")
         self.assertEqual(self.lmp.extract_global("procgrid"), None)
 
+    def test_extract_pair1(self):
+        self.lmp.command("region box block 0 1 0 1 0 1")
+        self.lmp.command("create_box 3 box")
+        self.lmp.command("mass * 1.0")
+        self.lmp.command("pair_style lj/cut 3.0")
+        self.lmp.command("pair_coeff 1 1 1.0 1.0")
+        self.lmp.command("pair_coeff 2 2 1.5 2.0")
+        self.lmp.command("pair_coeff 3 3 1.0 3.0")
+        self.lmp.command("run 0 post no")
+        self.assertEqual(self.lmp.extract_pair_dimension("epsilon"), 2)
+        self.assertEqual(self.lmp.extract_pair_dimension("sigma"), 2)
+        self.assertEqual(self.lmp.extract_pair_dimension("cut_coul"), None)
+        sigma = self.lmp.extract_pair("sigma")
+        self.assertEqual(sigma[1][1], 1.0)
+        self.assertEqual(sigma[2][2], 2.0)
+        self.assertEqual(sigma[3][3], 3.0)
+        self.assertEqual(sigma[1][2], math.sqrt(2.0))
+
+    @unittest.skipIf(not has_streitz, "Pair extract for coul/streitz test")
+    def test_extract_pair2(self):
+        self.lmp.command("units metal")
+        self.lmp.command("atom_style charge")
+        self.lmp.command("region box block 0 1 0 1 0 1")
+        self.lmp.command("create_box 2 box")
+        self.lmp.command("mass * 1.0")
+        self.lmp.command("pair_style coul/streitz 12.0 wolf 0.31")
+        self.lmp.command("pair_coeff * * AlO.streitz Al O")
+        self.lmp.command("run 0 post no")
+
+        self.assertEqual(self.lmp.extract_pair_dimension("chi"), 1)
+        self.assertEqual(self.lmp.extract_pair_dimension("scale"), 2)
+        self.assertEqual(self.lmp.extract_pair_dimension("cut_coul"), 0)
+        self.assertEqual(self.lmp.extract_pair_dimension("epsilon"), None)
+
+        self.assertEqual(self.lmp.extract_pair("cut_coul"), 12.0)
+        self.assertEqual(self.lmp.extract_pair("chi"), [0.0, 0.0, 5.484763])
+        scale = self.lmp.extract_pair("scale")
+        self.assertEqual(scale[0][0], 0.0);
+        self.assertEqual(scale[0][1], 0.0);
+        self.assertEqual(scale[1][1], 1.0);
+        self.assertEqual(scale[1][2], 1.0);
+        self.assertEqual(scale[2][2], 1.0);
+
     def test_create_atoms(self):
         self.lmp.command("boundary f p m")
         self.lmp.command("region box block 0 10 0 10 0 10")