Add Latexify extension

Project.toml

@@ -28,10 +28,12 @@ Tricks = "410a4b4d-49e4-4fbc-ab6d-cb71b17b3775"
 
 [weakdeps]
 JSON3 = "0f8b85d8-7281-11e9-16c2-39a750bddbf1"
+Latexify = "23fbe1c1-3f47-55db-b15f-69d7ec21a316"
 SymbolicUtils = "d1185830-fcd6-423d-90d6-eec64667417b"
 
 [extensions]
 SymbolicRegressionJSON3Ext = "JSON3"
+SymbolicRegressionLatexifyExt = "Latexify"
 SymbolicRegressionSymbolicUtilsExt = "SymbolicUtils"
 
 [compat]
@@ -40,6 +42,7 @@ Compat = "^4.2"
 DynamicExpressions = "0.13"
 DynamicQuantities = "0.10"
 JSON3 = "1"
+Latexify = "0.16"
 LineSearches = "7"
 LossFunctions = "0.10, 0.11"
 MLJModelInterface = "1.5, 1.6, 1.7, 1.8"
@@ -60,6 +63,7 @@ julia = "1.6"
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
 JSON3 = "0f8b85d8-7281-11e9-16c2-39a750bddbf1"
+Latexify = "23fbe1c1-3f47-55db-b15f-69d7ec21a316"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 MLJBase = "a7f614a8-145f-11e9-1d2a-a57a1082229d"
 MLJTestInterface = "72560011-54dd-4dc2-94f3-c5de45b75ecd"
@@ -70,4 +74,4 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 Zygote = "e88e6eb3-aa80-5325-afca-941959d7151f"
 
 [targets]
-test = ["Test", "SafeTestsets", "Aqua", "ForwardDiff", "LinearAlgebra", "JSON3", "MLJBase", "MLJTestInterface", "Suppressor", "SymbolicUtils", "Zygote"]
+test = ["Test", "SafeTestsets", "Aqua", "ForwardDiff", "Latexify", "LinearAlgebra", "JSON3", "MLJBase", "MLJTestInterface", "Suppressor", "SymbolicUtils", "Zygote"]

ext/SymbolicRegressionLatexifyExt.jl

@@ -0,0 +1,24 @@
+module SymbolicRegressionLatexifyExt
+
+using SymbolicRegression: Options, Node, string_tree
+using Latexify
+
+@latexrecipe function latexify_node(::Node)
+    throw(
+        ArgumentError(
+            "You must pass an Options object to latexify in addition to the `Node` object"
+        ),
+    )
+end
+
+@latexrecipe function latexify_node(tree::Node, options::Options; variable_names=:default)
+    s = string_tree(
+        tree,
+        options;
+        raw=false,
+        variable_names=(variable_names == :default ? nothing : variable_names),
+    )
+    return s
+end
+
+end

test/test_latexify.jl

@@ -0,0 +1,39 @@
+using SymbolicRegression
+using Latexify: latexify, @L_str
+
+options = Options(; binary_operators=(+, -, *, /), unary_operators=(cos, sin))
+x1, x2, x3 = (i -> Node(Float64; feature=i)).(1:3)
+tree = cos(x1 - 0.9) * x2 - 0.9 / x3
+
+latex_output = latexify(tree, options)
+@test latex_output == L"$\cos\left( x_1 - 0.9 \right) \cdot x_2 - \frac{0.9}{x_3}$"
+
+latex_output_diff_names = latexify(tree, options; variable_names=["a", "b", "c"])
+@test latex_output_diff_names == L"$\cos\left( a - 0.9 \right) \cdot b - \frac{0.9}{c}$"
+
+@test_throws ArgumentError latexify(tree)
+VERSION >= v"1.9" &&
+    @test_throws "You must pass an Options object to latexify" latexify(tree)
+
+# With weird operators:
+options = Options(; binary_operators=(-,), unary_operators=(erf,))
+@extend_operators options
+x1 = Node(; feature=1)
+tree = erf(x1 - 0.9)
+@test latexify(tree, options) == L"$\mathrm{erf}\left( x_1 - 0.9 \right)$"
+
+# With user-defined operator:
+myop(x, y) = x + y
+options = Options(; binary_operators=(myop,))
+@extend_operators options
+x1 = Node(; feature=1)
+tree = myop(x1, 0.9)
+@test latexify(tree, options) == L"$\mathrm{myop}\left( x_1, 0.9 \right)$"
+
+# Issue with operators that have underscores:
+my_op(x, y) = x + y
+options = Options(; binary_operators=(my_op,))
+@extend_operators options
+x1 = Node(; feature=1)
+tree = my_op(x1, 0.9)
+@test_broken latexify(tree, options) == L"$\mathrm{myop}\left( x_1, 0.9 \right)$"

test/unittest.jl

@@ -103,3 +103,7 @@ end
 @safetestset "Dataset" begin
     include("test_dataset.jl")
 end
+
+@safetestset "Latexify" begin
+    include("test_latexify.jl")
+end