Merge pull request #435 from isuruf/atan2

Fix converting atan2 to sympy

Author: isuruf

symengine/lib/symengine_wrapper.pyx

@@ -2635,6 +2635,14 @@ class atan2(Function):
         cdef Basic Y = sympify(y)
         return c2py(symengine.atan2(X.thisptr, Y.thisptr))
 
+    def _sympy_(self):
+        import sympy
+        return sympy.atan2(*self.args_as_sympy())
+
+    def _sage_(self):
+        import sage.all as sage
+        return sage.atan2(*self.args_as_sage())
+
 # For backwards compatibility
 
 Sin = sin

symengine/tests/test_sympy_conv.py

@@ -2,7 +2,7 @@
         function_symbol, I, E, pi, oo, zoo, nan, true, false,
         exp, gamma, have_mpfr, have_mpc, DenseMatrix, sin, cos, tan, cot,
         csc, sec, asin, acos, atan, acot, acsc, asec, sinh, cosh, tanh, coth,
-        asinh, acosh, atanh, acoth, Add, Mul, Pow, diff, GoldenRatio,
+        asinh, acosh, atanh, acoth, atan2, Add, Mul, Pow, diff, GoldenRatio,
         Catalan, EulerGamma, UnevaluatedExpr, RealDouble)
 from symengine.lib.symengine_wrapper import (Subs, Derivative, RealMPFR,
         ComplexMPC, PyNumber, Function, LambertW, zeta, dirichlet_eta,
@@ -171,6 +171,7 @@ def test_conv7():
     assert acot(x/3) == acot(sympy.Symbol("x") / 3)
     assert acsc(x/3) == acsc(sympy.Symbol("x") / 3)
     assert asec(x/3) == asec(sympy.Symbol("x") / 3)
+    assert atan2(x/3, y) == atan2(sympy.Symbol("x") / 3, sympy.Symbol("y"))
 
     assert sin(x/3)._sympy_() == sympy.sin(sympy.Symbol("x") / 3)
     assert sin(x/3)._sympy_() != sympy.cos(sympy.Symbol("x") / 3)
@@ -185,6 +186,22 @@ def test_conv7():
     assert acot(x/3)._sympy_() == sympy.acot(sympy.Symbol("x") / 3)
     assert acsc(x/3)._sympy_() == sympy.acsc(sympy.Symbol("x") / 3)
     assert asec(x/3)._sympy_() == sympy.asec(sympy.Symbol("x") / 3)
+    assert atan2(x/3, y)._sympy_() == sympy.atan2(sympy.Symbol("x") / 3, sympy.Symbol("y"))
+
+    assert sympy.sympify(sin(x/3)) == sympy.sin(sympy.Symbol("x") / 3)
+    assert sympy.sympify(sin(x/3)) != sympy.cos(sympy.Symbol("x") / 3)
+    assert sympy.sympify(cos(x/3)) == sympy.cos(sympy.Symbol("x") / 3)
+    assert sympy.sympify(tan(x/3)) == sympy.tan(sympy.Symbol("x") / 3)
+    assert sympy.sympify(cot(x/3)) == sympy.cot(sympy.Symbol("x") / 3)
+    assert sympy.sympify(csc(x/3)) == sympy.csc(sympy.Symbol("x") / 3)
+    assert sympy.sympify(sec(x/3)) == sympy.sec(sympy.Symbol("x") / 3)
+    assert sympy.sympify(asin(x/3)) == sympy.asin(sympy.Symbol("x") / 3)
+    assert sympy.sympify(acos(x/3)) == sympy.acos(sympy.Symbol("x") / 3)
+    assert sympy.sympify(atan(x/3)) == sympy.atan(sympy.Symbol("x") / 3)
+    assert sympy.sympify(acot(x/3)) == sympy.acot(sympy.Symbol("x") / 3)
+    assert sympy.sympify(acsc(x/3)) == sympy.acsc(sympy.Symbol("x") / 3)
+    assert sympy.sympify(asec(x/3)) == sympy.asec(sympy.Symbol("x") / 3)
+    assert sympy.sympify(atan2(x/3, y)) == sympy.atan2(sympy.Symbol("x") / 3, sympy.Symbol("y"))
 
 
 @unittest.skipIf(not have_sympy, "SymPy not installed")
@@ -204,6 +221,7 @@ def test_conv7b():
     assert sympify(sympy.acot(x/3)) == acot(Symbol("x") / 3)
     assert sympify(sympy.acsc(x/3)) == acsc(Symbol("x") / 3)
     assert sympify(sympy.asec(x/3)) == asec(Symbol("x") / 3)
+    assert sympify(sympy.atan2(x/3, y)) == atan2(Symbol("x") / 3, Symbol("y"))
 
 
 @unittest.skipIf(not have_sympy, "SymPy not installed")