Added docstrings

Author: mfalt

src/Polynomials.jl

@@ -580,11 +580,11 @@ polyder(a::AbstractArray{Poly{T}}, order::Int = 1) where {T} = map(p->polyder(p,
 
 # compute the roots of a polynomial
 """
-    roots(p::Poly)
+    roots(p::Poly; kwargs...)
 
 Return the roots (zeros) of `p`, with multiplicity. The number of roots
 returned is equal to the order of `p`. The returned roots may be real or
-complex.
+complex. Keyword arguments `kwargs` are sent to the `eigvals` call.
 
 # Examples
 
@@ -610,6 +610,17 @@ julia> roots(poly([1,2,3,4]))
  3.0
  2.0
  1.0
+
+julia> roots(Poly([1, 0, -1]), scale=false, permute=false)
+2-element Array{Float64,1}:
+ -1.0
+  1.0
+
+# In Julia > 1.2
+julia> roots(Poly([1, 0, -1]), sortby = t -> -real(t))
+2-element Array{Float64,1}:
+  1.0
+ -1.0
 ```
 """
 function roots(p::Poly{T}; kwargs...) where {T}
@@ -639,7 +650,7 @@ function roots(p::Poly{T}; kwargs...) where {T}
     r[1:n] = D
     return r
 end
-roots(p::Poly{Rational{T}}) where {T} = roots(convert(Poly{promote_type(T, Float64)}, p))
+roots(p::Poly{Rational{T}}; kwargs...) where {T} = roots(convert(Poly{promote_type(T, Float64)}, p); kwargs...)
 
 ## compute gcd of two polynomials
 """

src/show.jl

@@ -70,13 +70,14 @@ end
 ###
 
 """
-    printpoly(io::IO, p::Poly, mimetype = MIME"text/plain"(); descending_powers=false, offset::Int=0)
+    printpoly(io::IO, p::Poly, mimetype = MIME"text/plain"(); descending_powers=false, offset::Int=0, var=p.var)
 
 Print a human-readable representation of the polynomial `p` to `io`. The MIME
 types "text/plain" (default), "text/latex", and "text/html" are supported. By
 default, the terms are in order of ascending powers, matching the order in
 `coeffs(p)`; specifying `descending_powers=true` reverses the order.
 `offset` allows for an integer number to be added to the exponent, just for printing.
+`var` allows for overriding the variable used for printing.
 
 # Examples
 ```jldoctest
@@ -88,6 +89,8 @@ julia> printpoly(stdout, Poly([2, 3, 1], :z), descending_powers=true, offset=-2)
 1 + 3*z^-1 + 2*z^-2
 julia> printpoly(stdout, Poly([-1, 0, 1], :z), offset=-1, descending_powers=true)
 z - z^-1
+julia> printpoly(stdout, Poly([-1, 0, 1], :z), offset=-1, descending_powers=true, var=:x)
+x - x^-1
 ```
 """
 function printpoly(io::IO, p::Poly{T}, mimetype=MIME"text/plain"(); descending_powers=false, offset::Int=0, var=p.var) where {T}