Merge pull request #1828 from isuruf/exp

Fix exp(x + num)/exp(x) not evaluating
symengine · Sep 3, 2021 · e6716b6 · e6716b6
2 parents 01fd6b4 + c50264e
commit e6716b6
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Showing 4 changed files with 26 additions and 0 deletions.
diff --git a/bin/test_symengine_unix.sh b/bin/test_symengine_unix.sh
@@ -13,6 +13,9 @@ if [[ "$(uname)" == "Linux" ]]; then
 fi
 
 if [[ "$TEST_CLANG_FORMAT" == "yes" ]]; then
+  export conda_pkgs="clang-tools=11"
+  source bin/install_travis.sh
+  ln -sf $CONDA_PREFIX/bin/clang-format $CONDA_PREFIX/bin/clang-format-11
   source bin/travis_clang_format.sh
 elif [[ "$CONDA_ENV_FILE" == *"matchpycpp"* ]]; then
   source bin/install_travis.sh

diff --git a/symengine/mul.cpp b/symengine/mul.cpp
@@ -296,6 +296,17 @@ void Mul::dict_add_term_new(const Ptr<RCP<const Number>> &coef,
                     d.erase(it);
                     m->power_num(outArg(*coef), d, exp_);
                 }
+            } else if (eq(*it->first, *E)) {
+                RCP<const Number> p = rcp_static_cast<const Number>(it->second);
+                if (not p->is_exact()) {
+                    // Evaluate E**0.2, but not E**2
+                    RCP<const Basic> exp_ = p->get_eval().exp(*p);
+                    if (is_a_Number(*exp_)) {
+                        imulnum(outArg(*coef),
+                                rcp_static_cast<const Number>(exp_));
+                        d.erase(it);
+                    }
+                }
             }
         }
     }

diff --git a/symengine/tests/basic/test_arit.cpp b/symengine/tests/basic/test_arit.cpp
@@ -293,6 +293,12 @@ TEST_CASE("Mul: arit", "[arit]")
               real_double(0.2)});
     REQUIRE(std::abs(down_cast<const RealDouble &>(*r2).i - 0.03) < 1e-12);
 
+    r1 = real_double(0.1);
+    r2 = div(exp(add(x, r1)), exp(x));
+    REQUIRE(is_a<RealDouble>(*r2));
+    REQUIRE(std::abs(down_cast<const RealDouble &>(*r2).i - 1.10517091807565)
+            < 1e-10);
+
     // Real * 0 = 0 * Real = 0
     r1 = real_double(0.0);
     r2 = integer(0);

diff --git a/symengine/tests/basic/test_infinity.cpp b/symengine/tests/basic/test_infinity.cpp
@@ -8,9 +8,11 @@
 #include <symengine/constants.h>
 #include <symengine/symengine_exception.h>
 #include <symengine/functions.h>
+#include <symengine/add.h>
 #include <symengine/pow.h>
 #include <symengine/complex_double.h>
 
+using SymEngine::add;
 using SymEngine::Basic;
 using SymEngine::Complex;
 using SymEngine::complex_double;
@@ -329,6 +331,10 @@ TEST_CASE("Powers to Infinity", "[Infinity]")
     CHECK_THROWS_AS(integer(10)->pow(*c), SymEngineException &);
     CHECK_THROWS_AS(integer(-3)->pow(*c), SymEngineException &);
     CHECK_THROWS_AS(cx->pow(*c), NotImplementedError &);
+
+    RCP<const Basic> x = symbol("x");
+    RCP<const Basic> r = exp(add(c, x));
+    CHECK_THROWS_AS(div(r, exp(x)), DomainError &);
 }
 
 TEST_CASE("Evaluate Class of Infinity", "[Infinity]")