mul_coefficients for ConstantOperator (#382)

Author: jishnub

Project.toml

@@ -1,6 +1,6 @@
 name = "ApproxFunBase"
 uuid = "fbd15aa5-315a-5a7d-a8a4-24992e37be05"
-version = "0.7.72"
+version = "0.7.73"
 
 [deps]
 AbstractFFTs = "621f4979-c628-5d54-868e-fcf4e3e8185c"

src/Operators/banded/ConstantOperator.jl

@@ -60,6 +60,9 @@ for op in (:+,:-)
     @eval ($op)(A::ConstantOperator,B::ConstantOperator) = ConstantOperator($op(A.λ,B.λ))
 end
 
+mul_coefficients(A::ConstantOperator, b) = A.λ * b
+mul_coefficients!(A::ConstantOperator, b) = b .*= A.λ
+
 
 ## Basis Functional
 

test/runtests.jl

@@ -348,6 +348,13 @@ end
         C2 = C * C
         @test domainspace(C2) == PointSpace(1:4)
         @test convert(Number, C2) == 1
+
+        v = Float64[i^2 for i in 1:4]
+        f = Fun(PointSpace(1:4), v)
+        g = C * f
+        @test g ≈ f
+        ApproxFunBase.mul_coefficients!(Operator(2I), v)
+        @test v ≈ Float64[2i^2 for i in 1:4]
     end
 end