Merge pull request #162 from otaithleigh/master

Add US customary units kip and ksi

unyt/_unit_lookup_table.py

@@ -166,6 +166,16 @@
                 False,
             ),
         ),
+        (
+            "kip",
+            (
+                1000 * kg_per_pound * standard_gravity_m_per_s2,
+                dimensions.force,
+                0.0,
+                r"\rm{kip}",
+                False,
+            ),
+        ),
         ("lb", (kg_per_pound, dimensions.mass, 0.0, r"\rm{lb}", False)),
         ("atm", (pascal_per_atm, dimensions.pressure, 0.0, r"\rm{atm}", False)),
         ("hp", (watt_per_horsepower, dimensions.power, 0.0, r"\rm{hp}", False)),
@@ -193,6 +203,16 @@
                 False,
             ),
         ),
+        (
+            "ksi",
+            (
+                1000 * kg_per_pound * standard_gravity_m_per_s2 / m_per_inch ** 2,
+                dimensions.pressure,
+                0.0,
+                r"\rm{ksi}",
+                False,
+            ),
+        ),
         ("smoot", (1.7018, dimensions.length, 0.0, r"\rm{smoot}", False)),
         # dimensionless stuff
         ("dimensionless", (1.0, dimensions.dimensionless, 0.0, r"", False)),
@@ -443,13 +463,15 @@
         ("degF", ("degree_fahrenheit", "degree_Fahrenheit", "fahrenheit", "°F")),
         ("R", ("degree_rankine", "rankine")),
         ("lbf", ("pound_force",)),
+        ("kip", ("kilopound", "kipf")),
         ("lb", ("pound", "pound_mass", "lbm")),
         ("atm", ("atmosphere",)),
         ("hp", ("horsepower",)),
         ("oz", ("ounce",)),
         ("cal", ("calorie",)),
         ("BTU", ("british_thermal_unit",)),
         ("psi", ("pounds_per_square_inch",)),
+        ("ksi", ("kips_per_square_inch",)),
         # dimensionless stuff
         ("dimensionless", ("_", "")),
         ("B", ("bel",)),

unyt/tests/test_unyt_array.py

@@ -2415,3 +2415,11 @@ def test_delta_degF():
 
 def test_mil():
     assert_allclose_units(unyt_quantity(1, "mil"), unyt_quantity(0.001, "inch"))
+
+
+def test_kip():
+    assert_allclose_units(unyt_quantity(1, "lbf"), unyt_quantity(0.001, "kip"))
+
+
+def test_ksi():
+    assert_allclose_units(unyt_quantity(1, "lbf/inch**2"), unyt_quantity(0.001, "ksi"))