From e49f153a9087e1ab20ee65a440a02c15a4939054 Mon Sep 17 00:00:00 2001
From: Christopher Rackauckas <accounts@chrisrackauckas.com>
Date: Tue, 27 Aug 2024 10:17:24 -0400
Subject: [PATCH] Add symbolics_to_float converter

---
 docs/src/manual/expression_manipulation.md |  2 +-
 src/utils.jl                               | 24 ++++++++++++++++++++++
 test/runtests.jl                           |  1 +
 test/utils.jl                              |  6 ++++++
 4 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/docs/src/manual/expression_manipulation.md b/docs/src/manual/expression_manipulation.md
index 102aa985c..85c3be87d 100644
--- a/docs/src/manual/expression_manipulation.md
+++ b/docs/src/manual/expression_manipulation.md
@@ -25,7 +25,6 @@ Other additional manipulation functions are given below.
 Symbolics.get_variables
 Symbolics.tosymbol
 Symbolics.diff2term
-Symbolics.solve_for
 Symbolics.degree
 Symbolics.coeff
 Symbolics.replace
@@ -33,4 +32,5 @@ Symbolics.occursin
 Symbolics.filterchildren
 Symbolics.fixpoint_sub
 Symbolics.fast_substitute
+Symbolics.symbolic_to_float
 ```
diff --git a/src/utils.jl b/src/utils.jl
index 7628e1394..5e34e2d66 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -414,3 +414,27 @@ symbolic expressions mapping variables w.r.t pvar2sym
 function poly_to_symbol(polys, pvar2sym, sym2term, ::Type{T}) where {T}
     map(f -> PolyForm{T}(f, pvar2sym, sym2term), polys)
 end
+
+"""
+    symbolic_to_float(x::Union{Num, BasicSymbolic})::Union{AbstractFloat, BasicSymbolic}
+
+If the symbolic value is exactly equal to a number, converts the symbolic value
+to a floating point number. Otherwise retains the symbolic value.
+
+## Examples
+
+```julia
+symbolic_to_float((1//2 * x)/x) # 0.5
+symbolic_to_float((1/2 * x)/x) # 0.5
+symbolic_to_float((1//2)*√(279//4)) # 4.175823272122517
+```
+"""
+function symbolic_to_float end
+symbolic_to_float(x::Num) = symbolic_to_float(unwrap(x))
+function symbolic_to_float(x::SymbolicUtils.BasicSymbolic)
+    if _x isa Number
+        return _x
+    else
+        substitute(x,Dict())
+    end
+end
diff --git a/test/runtests.jl b/test/runtests.jl
index 4fc68f740..1aaafe4eb 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -27,6 +27,7 @@ if GROUP == "All" || GROUP == "Core"
         @safetestset "Semi-polynomial" begin include("semipoly.jl") end
         @safetestset "Fuzz Arrays" begin include("fuzz-arrays.jl") end
         @safetestset "Differentiation Test" begin include("diff.jl") end
+        @safetestset "Utils Test" begin include("utils.jl") end
         @safetestset "ADTypes Test" begin include("adtypes.jl") end
         @safetestset "Difference Test" begin include("difference.jl") end
         @safetestset "Degree Test" begin include("degree.jl") end
diff --git a/test/utils.jl b/test/utils.jl
index dfa0ff31c..386da8613 100644
--- a/test/utils.jl
+++ b/test/utils.jl
@@ -1,4 +1,5 @@
 using Symbolics
+using Symbolics: symbolic_to_float
 
 @testset "get_variables" begin
     @variables t x y z(t)
@@ -19,3 +20,8 @@ using Symbolics
     sorted_vars2 = Symbolics.get_variables(ex2; sort = true)
     @test isequal(sorted_vars2, [x, y])
 end
+
+symbolic_to_float((1//2 * x)/x) isa Float64
+symbolic_to_float((1/2 * x)/x) isa Float64
+symbolic_to_float((1//2)*√(279//4)) isa Float64
+symbolic_to_float((-1//2)*√(279//4)) isa Float64