no offsets

src/derivative.jl

@@ -24,6 +24,7 @@ Set `check` to `Val{false}()` to disable tag checking. This can lead to perturba
 """
 @inline function derivative(f!, y::AbstractArray, x::Real,
                             cfg::DerivativeConfig{T} = DerivativeConfig(f!, y, x), ::Val{CHK}=Val{true}()) where {T, CHK}
+    require_one_based_indexing(y)
     CHK && checktag(T, f!, x)
     ydual = cfg.duals
     seed!(ydual, y)
@@ -42,6 +43,7 @@ This method assumes that `isa(f(x), Union{Real,AbstractArray})`.
 """
 @inline function derivative!(result::Union{AbstractArray,DiffResult},
                              f::F, x::R) where {F,R<:Real}
+    require_one_based_indexing(result)
     T = typeof(Tag(f, R))
     ydual = f(Dual{T}(x, one(x)))
     result = extract_value!(T, result, ydual)
@@ -60,6 +62,7 @@ Set `check` to `Val{false}()` to disable tag checking. This can lead to perturba
 @inline function derivative!(result::Union{AbstractArray,DiffResult},
                              f!, y::AbstractArray, x::Real,
                              cfg::DerivativeConfig{T} = DerivativeConfig(f!, y, x), ::Val{CHK}=Val{true}()) where {T, CHK}
+    require_one_based_indexing(result, y)
     CHK && checktag(T, f!, x)
     ydual = cfg.duals
     seed!(ydual, y)

src/gradient.jl

@@ -14,6 +14,7 @@ This method assumes that `isa(f(x), Real)`.
 Set `check` to `Val{false}()` to disable tag checking. This can lead to perturbation confusion, so should be used with care.
 """
 function gradient(f, x::AbstractArray, cfg::GradientConfig{T} = GradientConfig(f, x), ::Val{CHK}=Val{true}()) where {T, CHK}
+    require_one_based_indexing(x)
     CHK && checktag(T, f, x)
     if chunksize(cfg) == length(x)
         return vector_mode_gradient(f, x, cfg)
@@ -32,6 +33,7 @@ This method assumes that `isa(f(x), Real)`.
 
 """
 function gradient!(result::Union{AbstractArray,DiffResult}, f::F, x::AbstractArray, cfg::GradientConfig{T} = GradientConfig(f, x), ::Val{CHK}=Val{true}()) where {T, CHK, F}
+    require_one_based_indexing(result, x)
     CHK && checktag(T, f, x)
     if chunksize(cfg) == length(x)
         vector_mode_gradient!(result, f, x, cfg)

src/hessian.jl

@@ -12,6 +12,7 @@ This method assumes that `isa(f(x), Real)`.
 Set `check` to `Val{false}()` to disable tag checking. This can lead to perturbation confusion, so should be used with care.
 """
 function hessian(f, x::AbstractArray, cfg::HessianConfig{T} = HessianConfig(f, x), ::Val{CHK}=Val{true}()) where {T,CHK}
+    require_one_based_indexing(x)
     CHK && checktag(T, f, x)
     ∇f = y -> gradient(f, y, cfg.gradient_config, Val{false}())
     return jacobian(∇f, x, cfg.jacobian_config, Val{false}())
@@ -28,6 +29,7 @@ This method assumes that `isa(f(x), Real)`.
 Set `check` to `Val{false}()` to disable tag checking. This can lead to perturbation confusion, so should be used with care.
 """
 function hessian!(result::AbstractArray, f, x::AbstractArray, cfg::HessianConfig{T} = HessianConfig(f, x), ::Val{CHK}=Val{true}()) where {T,CHK}
+    require_one_based_indexing(result, x)
     CHK && checktag(T, f, x)
     ∇f = y -> gradient(f, y, cfg.gradient_config, Val{false}())
     jacobian!(result, ∇f, x, cfg.jacobian_config, Val{false}())
@@ -62,6 +64,7 @@ because `isa(result, DiffResult)`, `cfg` is constructed as `HessianConfig(f, res
 Set `check` to `Val{false}()` to disable tag checking. This can lead to perturbation confusion, so should be used with care.
 """
 function hessian!(result::DiffResult, f, x::AbstractArray, cfg::HessianConfig{T} = HessianConfig(f, result, x), ::Val{CHK}=Val{true}()) where {T,CHK}
+    require_one_based_indexing(x)
     CHK && checktag(T, f, x)
     ∇f! = InnerGradientForHess(result, cfg, f)
     jacobian!(DiffResults.hessian(result), ∇f!, DiffResults.gradient(result), x, cfg.jacobian_config, Val{false}())

src/jacobian.jl

@@ -16,6 +16,7 @@ This method assumes that `isa(f(x), AbstractArray)`.
 Set `check` to `Val{false}()` to disable tag checking. This can lead to perturbation confusion, so should be used with care.
 """
 function jacobian(f, x::AbstractArray, cfg::JacobianConfig{T} = JacobianConfig(f, x), ::Val{CHK}=Val{true}()) where {T,CHK}
+    require_one_based_indexing(x)
     CHK && checktag(T, f, x)
     if chunksize(cfg) == length(x)
         return vector_mode_jacobian(f, x, cfg)
@@ -33,6 +34,7 @@ stored in `y`.
 Set `check` to `Val{false}()` to disable tag checking. This can lead to perturbation confusion, so should be used with care.
 """
 function jacobian(f!, y::AbstractArray, x::AbstractArray, cfg::JacobianConfig{T} = JacobianConfig(f!, y, x), ::Val{CHK}=Val{true}()) where {T, CHK}
+    require_one_based_indexing(y, x)
     CHK && checktag(T, f!, x)
     if chunksize(cfg) == length(x)
         return vector_mode_jacobian(f!, y, x, cfg)
@@ -53,6 +55,7 @@ This method assumes that `isa(f(x), AbstractArray)`.
 Set `check` to `Val{false}()` to disable tag checking. This can lead to perturbation confusion, so should be used with care.
 """
 function jacobian!(result::Union{AbstractArray,DiffResult}, f, x::AbstractArray, cfg::JacobianConfig{T} = JacobianConfig(f, x), ::Val{CHK}=Val{true}()) where {T, CHK}
+    require_one_based_indexing(result, x)
     CHK && checktag(T, f, x)
     if chunksize(cfg) == length(x)
         vector_mode_jacobian!(result, f, x, cfg)
@@ -73,6 +76,7 @@ This method assumes that `isa(f(x), AbstractArray)`.
 Set `check` to `Val{false}()` to disable tag checking. This can lead to perturbation confusion, so should be used with care.
 """
 function jacobian!(result::Union{AbstractArray,DiffResult}, f!, y::AbstractArray, x::AbstractArray, cfg::JacobianConfig{T} = JacobianConfig(f!, y, x), ::Val{CHK}=Val{true}()) where {T,CHK}
+    require_one_based_indexing(result, y, x)
     CHK && checktag(T, f!, x)
     if chunksize(cfg) == length(x)
         vector_mode_jacobian!(result, f!, y, x, cfg)

src/prelude.jl

@@ -70,3 +70,8 @@ function qualified_cse!(expr)
     end
     return cse_expr
 end
+
+# This allows us to call `Base.require_one_based_indexing` in `gradient!` etc:
+Base.has_offset_axes(::DiffResults.DiffResult) = false
+# And this is only needed for VERSION < v"1.2"
+require_one_based_indexing(A...) = !has_offset_axes(A...) || throw(ArgumentError("offset arrays are not supported but got an array with index other than 1"))