Try both canonicalspaces in defaultConversion (#149)

* try both canonicalspaces in default_conversion

* version bump to v0.6.6

Project.toml

@@ -1,6 +1,6 @@
 name = "ApproxFunBase"
 uuid = "fbd15aa5-315a-5a7d-a8a4-24992e37be05"
-version = "0.6.5"
+version = "0.6.6"
 
 [deps]
 AbstractFFTs = "621f4979-c628-5d54-868e-fcf4e3e8185c"

src/Operators/banded/Conversion.jl

@@ -25,21 +25,32 @@ rangespace(C::ConcreteConversion)=C.rangespace
 
 
 
-
+function _implementconversionerror(a, b)
+    error("Implement Conversion from ", typeof(a), " to ", typeof(b))
+end
+function _defaultConversion(a, spa, b)
+    if typeof(spa) == typeof(a)
+        spb = canonicalspace(b)
+        if typeof(spb) == typeof(a)
+            _implementconversionerror(spb, b)
+        elseif typeof(spb) == typeof(b)
+            _implementconversionerror(a, spb)
+        else
+            return _defaultConversion(a, spb, b)
+        end
+    elseif typeof(spa) == typeof(b)
+        _implementconversionerror(a, spa)
+    end
+    Conversion(a, spa, b)
+end
 function defaultConversion(a::Space,b::Space)
     if a==b
         Conversion(a)
     elseif conversion_type(a,b)==NoSpace()
-        sp=canonicalspace(a)
-        if typeof(sp) == typeof(a)
-            error("Implement Conversion from " * string(typeof(sp)) * " to " * string(typeof(b)))
-        elseif typeof(sp) == typeof(b)
-            error("Implement Conversion from " * string(typeof(a)) * " to " * string(typeof(sp)))
-        else
-            Conversion(a,sp,b)
-        end
+        spa = canonicalspace(a)
+        _defaultConversion(a, spa, b)
     else
-        error("Implement Conversion from " * string(typeof(a)) * " to " * string(typeof(b)))
+        _implementconversionerror(a, b)
     end
 end
 

test/SpacesTest.jl

@@ -205,5 +205,17 @@ using ApproxFunOrthogonalPolynomials
                 end
             end
         end
+
+        @testset "conversion" begin
+            C12 = Conversion(Chebyshev(), NormalizedLegendre())
+            C21 = Conversion(NormalizedLegendre(), Chebyshev())
+            @test Matrix((C12 * C21)[1:10, 1:10]) ≈ I
+            @test Matrix((C21 * C12)[1:10, 1:10]) ≈ I
+
+            C12 = Conversion(Chebyshev(), NormalizedPolynomialSpace(Ultraspherical(1)))
+            C1C2 = Conversion(Ultraspherical(1), NormalizedPolynomialSpace(Ultraspherical(1))) *
+                    Conversion(Chebyshev(), Ultraspherical(1))
+            @test Matrix(C12[1:10, 1:10]) ≈ Matrix(C1C2[1:10, 1:10])
+        end
     end
 end