Merge pull request #74 from vpuri3/msic

small fixes

Author: ChrisRackauckas

src/basic.jl

@@ -199,6 +199,10 @@ function Base.adjoint(α::ScalarOperator) # TODO - test
     ScalarOperator(val; update_func=update_func)
 end
 Base.transpose(α::ScalarOperator) = α
+
+Base.one(::ScalarOperator{T}) where{T} = ScalarOperator(one(T))
+Base.zero(::ScalarOperator{T}) where{T} = ScalarOperator(zero(T))
+
 Base.one(::Type{<:AbstractSciMLOperator}) = ScalarOperator(true)
 Base.zero(::Type{<:AbstractSciMLOperator}) = ScalarOperator(false)
 
@@ -527,6 +531,26 @@ for op in (
         @assert size(A, 2) == N
         A
     end
+
+    # null operator
+    @eval function Base.$op(::NullOperator{N}, A::ComposedOperator) where{N}
+        @assert size(A, 1) == N
+        zero(A)
+    end
+
+    @eval function Base.$op(A::ComposedOperator, ::NullOperator{N}) where{N}
+        @assert size(A, 2) == N
+        zero(A)
+    end
+
+    # scalar operator
+    @eval function Base.$op(λ::ScalarOperator, L::ComposedOperator)
+        ScaledOperator(λ, L)
+    end
+
+    @eval function Base.$op(L::ComposedOperator, λ::ScalarOperator)
+        ScaledOperator(λ, L)
+    end
 end
 
 Base.convert(::Type{AbstractMatrix}, L::ComposedOperator) = prod(op -> convert(AbstractMatrix, op), L.ops)

src/matrix.jl

@@ -79,7 +79,13 @@ LinearAlgebra.ldiv!(v::AbstractVecOrMat, L::MatrixOperator, u::AbstractVecOrMat)
 LinearAlgebra.ldiv!(L::MatrixOperator, u::AbstractVecOrMat) = ldiv!(L.A, u)
 
 """ Diagonal Operator """
-DiagonalOperator(u::AbstractVector) = MatrixOperator(Diagonal(u))
+function DiagonalOperator(u::AbstractVector; update_func=DEFAULT_UPDATE_FUNC)
+    function diag_update_func(A, u, p, t)
+        update_func(A.diag, u, p, t)
+        A
+    end
+    MatrixOperator(Diagonal(u); update_func=diag_update_func)
+end
 LinearAlgebra.Diagonal(L::MatrixOperator) = MatrixOperator(Diagonal(L.A))
 
 """