Add canonicalize kw and fix latexify tests

src/direct.jl

@@ -215,21 +215,31 @@ function sparsehessian(O, vars::AbstractVector; simplify = true)
     return H
 end
 
-function toexpr(O)
-    canonical, O = canonicalexpr(O)
-    canonical && return O
+"""
+    toexpr(O::Union{Symbolics,Num,Equation,AbstractArray}; canonicalize=true) -> Expr
+
+Convert `Symbolics` into `Expr`. If `canonicalize`, then we turn exprs like
+`x^(-n)` into `inv(x)^n` to avoid type error when evaluating.
+"""
+function toexpr(O; canonicalize=true)
+    if canonicalize
+        canonical, O = canonicalexpr(O)
+        canonical && return O
+    else
+        !istree(O) && return O
+    end
 
     op = operation(O)
     args = arguments(O)
     if op isa Differential
-        return :(derivative($(toexpr(args[1])),$(toexpr(op.x))))
+        return :(derivative($(toexpr(args[1]; canonicalize=canonicalize)),$(toexpr(op.x; canonicalize=canonicalize))))
     elseif op isa Sym
         isempty(args) && return nameof(op)
-        return Expr(:call, toexpr(op), toexpr.(args)...)
+        return Expr(:call, toexpr(op; canonicalize=canonicalize), toexpr(args; canonicalize=canonicalize)...)
     end
-    return Expr(:call, op, toexpr.(args)...)
+    return Expr(:call, op, toexpr(args; canonicalize=canonicalize)...)
 end
-toexpr(s::Sym) = nameof(s)
+toexpr(s::Sym; kw...) = nameof(s)
 
 """
     canonicalexpr(O) -> (canonical::Bool, expr)
@@ -242,18 +252,23 @@ function canonicalexpr(O)
     args = arguments(O)
     if op === (^)
         if length(args) == 2 && args[2] isa Number && args[2] < 0
-            expr = Expr(:call, ^, Expr(:call, inv, toexpr(args[1])), -args[2])
+            ex = toexpr(args[1])
+            if args[2] == -1
+                expr = Expr(:call, inv, ex)
+            else
+                expr = Expr(:call, ^, Expr(:call, inv, ex), -args[2])
+            end
             return true, expr
         end
     end
     return false, O
 end
 
-function toexpr(eq::Equation)
-    Expr(:(=), toexpr(eq.lhs), toexpr(eq.rhs))
+function toexpr(eq::Equation; kw...)
+    Expr(:(=), toexpr(eq.lhs; kw...), toexpr(eq.rhs; kw...))
 end
 
-toexpr(eq::AbstractArray) = toexpr.(eq)
-toexpr(x::Integer) = x
-toexpr(x::AbstractFloat) = x
-toexpr(x::Num) = toexpr(value(x))
+toexpr(eqs::AbstractArray; kw...) = map(eq->toexpr(eq; kw...), eqs)
+toexpr(x::Integer; kw...) = x
+toexpr(x::AbstractFloat; kw...) = x
+toexpr(x::Num; kw...) = toexpr(value(x); kw...)

src/latexify_recipes.jl

@@ -11,13 +11,13 @@ prettify_expr(expr::Expr) = Expr(expr.head, prettify_expr.(expr.args)...)
     # that latexify can deal with
 
     rhs = getfield.(eqs, :rhs)
-    rhs = prettify_expr.(toexpr.(rhs))
+    rhs = prettify_expr.(toexpr(rhs; canonicalize=false))
     rhs = [postwalk(x -> x isa Expr && length(x.args) == 1 ? x.args[1] : x, eq) for eq in rhs]
     rhs = [postwalk(x -> x isa Expr && x.args[1] == :derivative && length(x.args[2].args) == 2 ? :($(Symbol(:d, x.args[2]))/($(Symbol(:d, x.args[2].args[2])))) : x, eq) for eq in rhs]
     rhs = [postwalk(x -> x isa Expr && x.args[1] == :derivative ? "\\frac{d\\left($(Latexify.latexraw(x.args[2]))\\right)}{d$(Latexify.latexraw(x.args[3]))}" : x, eq) for eq in rhs]
 
     lhs = getfield.(eqs, :lhs)
-    lhs = prettify_expr.(toexpr.(lhs))
+    lhs = prettify_expr.(toexpr(lhs; canonicalize=false))
     lhs = [postwalk(x -> x isa Expr && length(x.args) == 1 ? x.args[1] : x, eq) for eq in lhs]
     lhs = [postwalk(x -> x isa Expr && x.args[1] == :derivative && length(x.args[2].args) == 2 ? :($(Symbol(:d, x.args[2]))/($(Symbol(:d, x.args[2].args[2])))) : x, eq) for eq in lhs]
     lhs = [postwalk(x -> x isa Expr && x.args[1] == :derivative ? "\\frac{d\\left($(Latexify.latexraw(x.args[2]))\\right)}{d$(Latexify.latexraw(x.args[3]))}" : x, eq) for eq in lhs]

test/latexify.jl

@@ -30,7 +30,7 @@ eqs = [D(x) ~ σ*(y-x)*D(x-y)/D(z),
 # Latexify.@generate_test latexify(eqs)
 @test latexify(eqs) == replace(
 raw"\begin{align}
-\frac{dx(t)}{dt} =& \frac{d\left(x\left( t \right) -1 \cdot y\left( t \right)\right)}{dt} \left( \mathrm{inv}\left( \frac{dz(t)}{dt} \right) \right)^{1} \sigma \left( y\left( t \right) -1 x\left( t \right) \right) \\
+\frac{dx(t)}{dt} =& \frac{d\left(x\left( t \right) -1 \cdot y\left( t \right)\right)}{dt} \left( \frac{dz(t)}{dt} \right)^{-1} \sigma \left( y\left( t \right) -1 x\left( t \right) \right) \\
 0 =& -1 y\left( t \right) + 0.1 x\left( t \right) \sigma \left( -1 z\left( t \right) + \rho \right) \\
 \frac{dz(t)}{dt} =& x\left( t \right) \left( y\left( t \right) \right)^{\frac{2}{3}} -1 z\left( t \right) \beta
 \end{align}
@@ -71,6 +71,6 @@ eqs = [D(x) ~ (1+cos(t))/(1+2*x)]
 
 @test latexify(eqs) == replace(
 raw"\begin{align}
-\frac{dx(t)}{dt} =& \left( 1 + \cos\left( t \right) \right) \left( \mathrm{inv}\left( 1 + 2 x\left( t \right) \right) \right)^{1}
+\frac{dx(t)}{dt} =& \left( 1 + \cos\left( t \right) \right) \left( 1 + 2 x\left( t \right) \right)^{-1}
 \end{align}
 ", "\r\n"=>"\n")