add documentation for functions

[hematthi]

EchelleCCFs.jl/src/mask_shapes/integrate.jl

Lines 6 to 77 in a639217

	struct IntegrateFixedOrder{FuncT,Order,NumGW,RetT} <: AbstractIntegrateFixedOrder where { FuncT, Order<:Integer, RetT<:Real }
	x::SVector{Order,RetT} # Technically, order = Order-1
	w::SVector{Order,RetT}
	gw::SVector{NumGW,RetT}
	f::FuncT
	end
	function IntegrateFixedOrder(f::FuncT,order::Integer) where { FuncT } #, RetT }
	@assert 1<=order <=10
	#ret_type = RetT
	ret_type = typeof(f(0.0))
	x,w,gw = QuadGK.cachedrule(ret_type,order)
	s_x = SVector{order+1,ret_type}(x)
	s_w = SVector{order+1,ret_type}(w)
	num_gw = floor(Int,(order+1)//2)
	s_gw = SVector{num_gw,ret_type}(gw)
	#s_gw = @SVector zeros(floor(Int,(order+1)//2))
	#s_gw[1:length(gw)] .= gw # since s_gw is generally too big
	IntegrateFixedOrder{FuncT,order+1,num_gw,ret_type}(s_x,s_w,s_gw,f)
	end
	function integrate_scalar_fixed_order_gauss(ifo::T, a::Real, b::Real) where { T<:AbstractIntegrateFixedOrder }
	s = convert(eltype(ifo.x), 0.5) * (b-a)
	n1 = 1 - (length(ifo.x) & 1) # 0 if even order, 1 if odd order
	# unroll first iterationof loop to get correct type of Ik and Ig
	fg = ifo.f(a + (1+ifo.x[2])*s) + ifo.f(a + (1-ifo.x[2])*s)
	Ig = fg * ifo.gw[1]
	for i = 2:length(ifo.gw)-n1
	fg = ifo.f(a + (1+ifo.x[2i])*s) + ifo.f(a + (1-ifo.x[2i])*s)
	Ig += fg * ifo.gw[i]
	end
	if n1 != 0 # even: Gauss rule does not include x == 0
	f0 = ifo.f(a + s)
	Ig += f0 * ifo.gw[end]
	end
	Ig_s = Ig * s # new variable since this may change the type
	return Ig_s
	end
	function integrate_scalar_fixed_order_kronrod(ifo::T, a::Real, b::Real) where { T<:AbstractIntegrateFixedOrder }
	s = convert(eltype(ifo.x), 0.5) * (b-a)
	n1 = 1 - (length(ifo.x) & 1) # 0 if even order, 1 if odd order
	# unroll first iterationof loop to get correct type of Ik and Ig
	fg = ifo.f(a + (1+ifo.x[2])*s) + ifo.f(a + (1-ifo.x[2])*s)
	fk = ifo.f(a + (1+ifo.x[1])*s) + ifo.f(a + (1-ifo.x[1])*s)
	Ik = fg * ifo.w[2] + fk * ifo.w[1]
	for i = 2:length(ifo.gw)-n1
	fg = ifo.f(a + (1+ifo.x[2i])*s) + ifo.f(a + (1-ifo.x[2i])*s)
	fk = ifo.f(a + (1+ifo.x[2i-1])*s) + ifo.f(a + (1-ifo.x[2i-1])*s)
	Ik += fg * ifo.w[2i] + fk * ifo.w[2i-1]
	end
	if n1 == 0 # even: Gauss rule does not include x == 0
	Ik += f(a + s) * ifo.w[end]
	else # odd: don't count x==0 twice in Gauss rule
	f0 = f(a + s)
	Ik += f0 * ifo.w[end] +
	(f(a + (1+ifo.x[end-1])*s) + f(a + (1-ifo.x[end-1])*s)) * ifo.w[end-1]
	end
	Ik_s = Ik * s # new variable since this may change the type
	return Ik_s
	end
	function (ifo::IntegrateFixedOrder)(a::Real, b::Real)
	integrate_scalar_fixed_order_gauss(ifo,a,b)
	end
	function error_estimate(ifo::T, a::Real, b::Real) where { T<:AbstractIntegrateFixedOrder }
	Ig = integrate_scalar_fixed_order_gauss(ifo,a,b)
	Ik = integrate_scalar_fixed_order_kronrod(ifo,a,b)
	return abs(Ik - Ig)
	end