From c98bce4c16c70db131091ece64a7f4192ee2c3af Mon Sep 17 00:00:00 2001
From: Matt Signorelli <mgs255@cornell.edu>
Date: Wed, 8 Jan 2025 12:31:38 -0500
Subject: [PATCH] signbit

---
 docs/src/man/n_all.md | 2 +-
 src/GTPSA.jl          | 1 +
 src/operators.jl      | 1 +
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/docs/src/man/n_all.md b/docs/src/man/n_all.md
index 925cc051..d9ec9c72 100644
--- a/docs/src/man/n_all.md
+++ b/docs/src/man/n_all.md
@@ -7,7 +7,7 @@ acos, atan, acsc, asec, acot, asinh, acosh, atanh, acsch, asech,
 acoth, zero, zeros, one, ones, real, imag, conj, angle, complex, 
 promote_rule, getindex, setindex!, ==, <, >, <=, >=, !=, isequal, 
 isless, isinf, isnan, show, copy!, lastindex, firstindex, rand, 
-unsafe_convert, eps, floatmin, floatmax
+unsafe_convert, eps, floatmin, floatmax, signbit
 ```
 
 `zeros` and `ones` are overloaded from Base so that allocated `TPS`s are placed in each element. Because of the mutability of `TPS`, if we didn't explicity overload these functions every element would correspond to the exact same heap-allocated TPS.
diff --git a/src/GTPSA.jl b/src/GTPSA.jl
index c5220183..4fbf4ba0 100644
--- a/src/GTPSA.jl
+++ b/src/GTPSA.jl
@@ -72,6 +72,7 @@ import Base:  +,
               eps,
               floatmin,
               floatmax,
+              signbit,
               delete!
 
 import LinearAlgebra: norm, mul!, copy_oftype, copymutable_oftype
diff --git a/src/operators.jl b/src/operators.jl
index d1adb0c2..e947c613 100644
--- a/src/operators.jl
+++ b/src/operators.jl
@@ -94,6 +94,7 @@ isnan(t1::TPS) = isnan(geti(t1, 0))
 eps(t1::TPS) = eps(numtype(t1))
 floatmin(t1::TPS) = floatmin(numtype(t1))
 floatmax(t1::TPS) = floatmax(numtype(t1))
+signbit(t1::TPS) = signbit(geti(t1, 0))
 
 # --- Compare entire TPS (monomial-by-monomial) ---
 isequal(t1::TPS{Float64},    t2::TPS{Float64})    = equ(t1, t2, 0)