Combining LaTeX with variables in PyPlot title

[stillyslalom]

julia> using Printf

julia> latexstring("Plot of the ", L"1^\mathrm{st}", " eigenfunction, corresponding to ", L"\lambda = ", 
                           @sprintf("%.10f", eigenvalue_approx[1]))

…or you could round the value: round(eigenvalue_approx[1], sigdigits=10)