InexactError: show_trace not work for complex numbers

[AuroraDysis]

One can use this code to reproduce the error

find_zero(sin, 1.0+1.0im, Order1(), verbose = true)

[jverzani]

Interesting. I was going to write back that we have a pretty strong assumption that the x values are real, save for Newton's method, but that isn't really the case, as it appears the secant method works with a complex valued starting point. This is just about the print method for verbose=true. I'll see if something can be done. Right now we use @sprintf so hopefully it is just an adjustment of the flag we use.

[jverzani]

In the meantime, if you want to see your trace, you could do something like this:

T = Complex{Float64}
tracks = Roots.Tracks(T,T)
find_zero(sin, 3.0+1.0im, Roots.Order1(); tracks=tracks)
tracks.xfₛ

[AuroraDysis]

I think the only method that needs to be changed is show_tracks.
We only need two functions to handle real and complex, say

where  {T <: Real}
where  {T <: Complex}

Here is the version for complex

function show_tracks(io::IO, s::Roots.Tracks{ComplexF64, ComplexF64}, M::Roots.AbstractUnivariateZeroMethod)

    # show (x,f(x))
    for (i, (xi, fxi)) in enumerate(s.xfₛ)
        println(
            io,
            @sprintf(
                "%s%s = (%.17g, %.17g),\t %s%s = (%.17g, %.17g)",
                "x",
                sprint(io -> Roots.unicode_subscript(io, i)),
                real(xi), imag(xi),
                "fx",
                sprint(io -> Roots.unicode_subscript(io, i)),
                real(fxi), imag(fxi)
            )
        )
    end

    # show bracketing
    i₀ = length(s.xfₛ)
    for (i, (a, b)) in enumerate(s.abₛ)
        j = i₀ + i
        println(
            io,
            @sprintf(
                "(%s%s, %s%s) = ( %.17g, %.17g )",
                "a",
                sprint(io -> unicode_subscript(io, j - 1)),
                "b",
                sprint(io -> unicode_subscript(io, j - 1)),
                a,
                b
            )
        )
    end
    println(io, "")
end

[jverzani]

Wow, I was about to write just what you wrote and voila, code already there!. Let me put it into a PR, unless you did that already.

[jverzani]

Closed by #337 Thanks so much.