improve default for sparsity

Author: huanglangwen

src/differentiation/compute_jacobian_ad.jl

@@ -81,7 +81,7 @@ function forwarddiff_color_jacobian!(J::AbstractMatrix{<:Number},
                 x::AbstractArray{<:Number};
                 dx = nothing,
                 color = eachindex(x),
-                sparsity = nothing)
+                sparsity = J isa SparseMatrixCSC ? J : nothing)
     forwarddiff_color_jacobian!(J,f,x,ForwardColorJacCache(f,x,dx=dx,color=color,sparsity=sparsity))
 end
 

test/test_ad.jl

@@ -31,12 +31,27 @@ _J = sparse(J)
 
 fcalls = 0
 _J1 = similar(_J)
-forwarddiff_color_jacobian!(_J1, f, x, color = repeat(1:3,10), sparsity=_J1)
+forwarddiff_color_jacobian!(_J1, f, x, color = repeat(1:3,10))
 @test _J1 ≈ J
 @test fcalls == 1
 
 fcalls = 0
-jac_cache = ForwardColorJacCache(f,x,color = repeat(1:3,10), sparsity=_J1)
+jac_cache = ForwardColorJacCache(f,x,color = repeat(1:3,10), sparsity = _J1)
 forwarddiff_color_jacobian!(_J1, f, x, jac_cache)
 @test _J1 ≈ J
 @test fcalls == 1
+
+fcalls = 0
+_J1 = similar(_J)
+_denseJ1 = collect(_J1)
+forwarddiff_color_jacobian!(_denseJ1, f, x, color = repeat(1:3,10), sparsity = _J1)
+@test _denseJ1 ≈ J
+@test fcalls == 1
+
+fcalls = 0
+_J1 = similar(_J)
+_denseJ1 = collect(_J1)
+jac_cache = ForwardColorJacCache(f,x,color = repeat(1:3,10), sparsity = _J1)
+forwarddiff_color_jacobian!(_denseJ1, f, x, jac_cache)
+@test _denseJ1 ≈ J
+@test fcalls == 1

test/test_integration.jl

@@ -38,13 +38,13 @@ J = DiffEqDiffTools.finite_difference_jacobian(f, rand(30))
 #Jacobian computed with coloring vectors
 fcalls = 0
 _J = similar(true_jac)
-DiffEqDiffTools.finite_difference_jacobian!(_J, f, rand(30), color = colors, sparsity=sparse(_J))
+DiffEqDiffTools.finite_difference_jacobian!(_J, f, rand(30), color = colors)
 @test fcalls == 4
 @test _J ≈ J
 
 fcalls = 0
 _J = similar(true_jac)
 _denseJ = collect(_J)
-DiffEqDiffTools.finite_difference_jacobian!(_denseJ, f, rand(30), color = colors, sparsity=sparse(_J))
+DiffEqDiffTools.finite_difference_jacobian!(_denseJ, f, rand(30), color = colors, sparsity=_J)
 @test fcalls == 4
 @test _denseJ ≈ J