Merge pull request #160 from hannes-uppman/norm

Fix norm

Author: JeffreySarnoff

src/math/linearalgebra/support.jl

@@ -16,7 +16,7 @@ function LinearAlgebra.norm(v::Array{DoubleFloat{T},N}, p::Real=2.0) where {N, T
     elseif p==2
         return vp = sqrt(sum(v .* v))
     else    
-        vp = sum((v).^(p))
+        vp = sum(abs.(v).^(p))
         r = inv(DoubleFloat{T}(p))
         return vp^r
     end    

test/linearalgebra.jl

@@ -29,6 +29,9 @@ using GenericLinearAlgebra, GenericSchur
     @test norm(Double64[2, 1]) ≈ norm(Float64[2, 1])
     @test norm(Double64[2, 1], 3.0) ≈ norm(Float64[2, 1], 3.0)
 
+    # issue #159
+    @test norm(Double64[-1, -1], 1) ≈ 2
+
     # issue #105
     for T in [Double16, Double32, Double64]
         for p in [0, 1.0, 2.0, Inf, -Inf]