fix bug printing complex leading terms with negative real part (#428)

* fix bug printing complex leading terms with negative real part

* fix docs too

Author: jverzani

Project.toml

@@ -2,7 +2,7 @@ name = "Polynomials"
 uuid = "f27b6e38-b328-58d1-80ce-0feddd5e7a45"
 license = "MIT"
 author = "JuliaMath"
-version = "3.1.4"
+version = "3.1.5"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

src/polynomials/LaurentPolynomial.jl

@@ -284,7 +284,7 @@ julia> z = variable(LaurentPolynomial, :z)
 LaurentPolynomial(1.0*z)
 
 julia> p = LaurentPolynomial([im, 1+im, 2 + im], -1, :z)
-LaurentPolynomial(im*z⁻¹ + 1 + im + (2 + im)z)
+LaurentPolynomial(im*z⁻¹ + (1 + im) + (2 + im)z)
 
 julia> conj(p)(conj(z)) ≈ conj(p(z))
 true

src/show.jl

@@ -255,7 +255,7 @@ function printcoefficient(io::IO, pj::S, j, mimetype) where {T,S <: Complex{T}}
     hasimag = !iszero(b) || isnan(b) || isinf(b)
 
     if hasreal && hasimag
-        iszero(j) || print(io, "(")
+        print(io, "(")
         print(io, a)
 
         # print b
@@ -277,7 +277,7 @@ function printcoefficient(io::IO, pj::S, j, mimetype) where {T,S <: Complex{T}}
         end
 
         print(io, imagsymbol(mimetype))
-        iszero(j) || print(io, ")")
+        print(io, ")")
 
     elseif hasreal
 

test/Poly.jl

@@ -295,7 +295,7 @@ p = Poly([1.0, 2.0, 3.0, 1.0])
 p = Poly([1, im])
 @test repr(p) == "$Poly(1 + im*x)"
 p = Poly([1+im, 1-im, -1+im, -1 - im])# minus signs
-@test repr(p) == "$Poly(1 + im + (1 - im)x - (1 - im)x^2 - (1 + im)x^3)"
+@test repr(p) == "$Poly((1 + im) + (1 - im)x - (1 - im)x^2 - (1 + im)x^3)"
 p = Poly([1.0, 0 + NaN*im, NaN, Inf, 0 - Inf*im]) # handle NaN or Inf appropriately
 @test repr(p) == "$Poly(1.0 + NaN*im*x + NaN*x^2 + Inf*x^3 - Inf*im*x^4)"
 
@@ -304,7 +304,7 @@ p = Poly([1,2,3])
 p = Poly([1//2, 2//3, 1])
 @test repr("text/latex", p) == "\$\\frac{1}{2} + \\frac{2}{3}\\cdot x + x^{2}\$"
 p = Poly([complex(1,1),complex(0,1),complex(1,0),complex(1,1)])
-@test repr("text/latex", p) == "\$1 + i + i\\cdot x + x^{2} + (1 + i)x^{3}\$"
+@test repr("text/latex", p) == "\$(1 + i) + i\\cdot x + x^{2} + (1 + i)x^{3}\$"
 
 # customized printing with printpoly
 function printpoly_to_string(args...; kwargs...)

test/StandardBasis.jl

@@ -1392,7 +1392,7 @@ end
         @test sprint(show, p) == "$P(1.0 + 2.0*x + 3.0*x^2)"
 
         p = P([1 + 1im, -2im])
-        @test sprint(show, p) == "$P(1 + im - 2im*x)"
+        @test sprint(show, p) == "$P((1 + im) - 2im*x)"
 
 
         p = P([1,2,3,1])  # leading coefficient of 1
@@ -1402,7 +1402,7 @@ end
         p = P([1, im])
         @test repr(p) == "$P(1 + im*x)"
         p = P([1 + im, 1 - im, -1 + im, -1 - im])# minus signs
-        @test repr(p) == "$P(1 + im + (1 - im)x - (1 - im)x^2 - (1 + im)x^3)"
+        @test repr(p) == "$P((1 + im) + (1 - im)x - (1 - im)x^2 - (1 + im)x^3)"
         p = P([1.0, 0 + NaN * im, NaN, Inf, 0 - Inf * im]) # handle NaN or Inf appropriately
         @test repr(p) == "$P(1.0 + NaN*im*x + NaN*x^2 + Inf*x^3 - Inf*im*x^4)"
 
@@ -1412,13 +1412,13 @@ end
         p = P([1 // 2, 2 // 3, 1])
         @test repr("text/latex", p) == "\$\\frac{1}{2} + \\frac{2}{3}\\cdot x + x^{2}\$"
         p = P([complex(1,1),complex(0,1),complex(1,0),complex(1,1)])
-        @test repr("text/latex", p) == "\$1 + i + i\\cdot x + x^{2} + (1 + i)x^{3}\$"
+        @test repr("text/latex", p) == "\$(1 + i) + i\\cdot x + x^{2} + (1 + i)x^{3}\$"
 
         @test printpoly_to_string(P([1,2,3], "y")) == "1 + 2*y + 3*y^2"
         @test printpoly_to_string(P([1,2,3], "y"), descending_powers = true) == "3*y^2 + 2*y + 1"
         @test printpoly_to_string(P([2, 3, 1], :z), descending_powers = true, offset = -2) == "1 + 3*z^-1 + 2*z^-2"
         @test printpoly_to_string(P([-1, 0, 1], :z), offset = -1, descending_powers = true) == "z - z^-1"
-        @test printpoly_to_string(P([complex(1,1),complex(1,-1)]),MIME"text/latex"()) == "1 + i + (1 - i)x"
+        @test printpoly_to_string(P([complex(1,1),complex(1,-1)]),MIME"text/latex"()) == "(1 + i) + (1 - i)x"
     end
 
     ## closed issues
@@ -1428,7 +1428,7 @@ end
     io=IOBuffer(); printpoly(io, p, compact=true, mulsymbol=""); @test String(take!(io)) == "1.23457 + 2.34568x"
 
     ## issue 278 with complex
-    @test printpoly_to_string(Polynomial([1 + im, 1, 2, im, 2im, 1+im, 1-im])) == "1 + im + x + 2*x^2 + im*x^3 + 2im*x^4 + (1 + im)x^5 + (1 - im)x^6"
+    @test printpoly_to_string(Polynomial([1 + im, 1, 2, im, 2im, 1+im, 1-im])) == "(1 + im) + x + 2*x^2 + im*x^3 + 2im*x^4 + (1 + im)x^5 + (1 - im)x^6"
 
     ## issue #320 (fix was broken)
     @test printpoly_to_string(Polynomial(BigInt[1,0,1], :y)) == "1 + y^2"