Add norm to Vcat and Hcat (#67)

* Add norm to Vcat and Hcat

* v0.12.2

* fix empty vcat norm

* don't overload normMinusInf

Author: dlfivefifty

Project.toml

@@ -1,6 +1,6 @@
 name = "LazyArrays"
 uuid = "5078a376-72f3-5289-bfd5-ec5146d43c02"
-version = "0.12.1"
+version = "0.12.2"
 
 [deps]
 FillArrays = "1a297f60-69ca-5386-bcde-b61e274b549b"

src/LazyArrays.jl

@@ -36,7 +36,8 @@ import Base.Broadcast: BroadcastStyle, AbstractArrayStyle, Broadcasted, broadcas
                         combine_eltypes, DefaultArrayStyle, instantiate, materialize,
                         materialize!, eltypes
 
-import LinearAlgebra: AbstractTriangular, AbstractQ, checksquare, pinv, fill!, tilebufsize, Abuf, Bbuf, Cbuf, dot, factorize, qr, lu, cholesky
+import LinearAlgebra: AbstractTriangular, AbstractQ, checksquare, pinv, fill!, tilebufsize, Abuf, Bbuf, Cbuf, dot, factorize, qr, lu, cholesky, 
+                        norm2, norm1, normInf, normMinusInf
 
 import LinearAlgebra.BLAS: BlasFloat, BlasReal, BlasComplex
 

src/lazyconcat.jl

@@ -538,3 +538,15 @@ end
 
 dot(a::CachedArray, b::AbstractArray) = materialize(Dot(a,b)) 
 dot(a::LazyArray, b::AbstractArray) = materialize(Dot(a,b)) 
+
+
+###
+# norm
+###
+
+for Cat in (:Vcat, :Hcat)
+    for (op,p) in ((:norm1,1), (:norm2,2), (:normInf,Inf))
+        @eval $op(a::$Cat) = $op(norm.(a.args,$p))
+    end
+    @eval normp(a::$Cat, p) = norm(norm.(a.args, p), p)
+end

test/concattests.jl

@@ -347,4 +347,12 @@ import LazyArrays: MemoryLayout, DenseColumnMajor, PaddedLayout, materialize!, M
         a[3] = 2; b[3] = 2; b[5]=0;
         @test a == b
     end 
+
+    @testset "norm" begin
+        for a in (Vcat(1,2,Fill(5,3)), Hcat([1,2],randn(2,2)), Vcat(1,Float64[])),
+            p in (-Inf, 0, 0.1, 1, 2, 3, Inf)
+            @show p
+            @test norm(a,p) ≈ norm(Array(a),p)
+        end
+    end
 end