API

input_pdf_map

The relevant mapping for use with QCDNUM and get_input_pdf_func.

abstract type PartonDensity.AbstractPDFParams

Abstract type for any PDF parametrisation.

struct BernsteinDirichletPDFParams <: AbstractPDFParams

Bernstein polynomial specification of input PDF parameters. Dirichlet-style treament.

Constructors:

• BernsteinDirichletPDFParams(; fields...)

Fields:

• param_type::Int64: Default: BERNSTEINDIRICHLETTYPE

• seed::Int64: Default: 0

• weights::Vector{Float64}: Default: ones(9)

• θ::Vector{Float64}: Default: rand(MersenneTwister(seed), Dirichlet(weights))

• bspoly_params::Vector{Vector{Int64}}: Default: [[0, 3], [0, 4], [1, 4]]

• bspoly_params_d::Vector{Vector{Int64}}: Default: bspoly_params

• initial_U::Vector{Float64}: Default: ones(length(bspoly_params) - 2)

• initial_D::Vector{Float64}: Default: ones(length(bspolyparamsd) - 2)

• U_list::Vector{Float64}: Default: getUDlist(θ[1], 2, initialU, bspolyparams)

• D_list::Vector{Float64}: Default: getUDlist(θ[2], 1, initialD, bspolyparams_d)

• λ_g1::Float64

• λ_g2::Float64

• K_g::Float64

• λ_q::Float64

• K_q::Float64

struct BernsteinPDFParams <: AbstractPDFParams

Bernstein polynomial specification of input PDF parameters. Valence-style treatment.

Constructors:

• BernsteinPDFParams(; fields...)

Fields:

• param_type::Int64: Default: BERNSTEIN_TYPE

• bspoly_params::Vector{Vector{Int64}}: Default: [[0, 3], [0, 4], [1, 4], [0, 5]]

• bspoly_params_d::Vector{Vector{Int64}}: Default: bspoly_params

• U_weights::Vector{Float64}: Default: zeros(length(bspoly_params))

• D_weights::Vector{Float64}: Default: zeros(length(bspoly_params))

• λ_g1::Float64

• λ_g2::Float64

• K_g::Float64

• λ_q::Float64

• K_q::Float64

• seed::Int64: Default: 0

• weights::Vector{Float64}: Default: ones(7)

• U_list::Vector{Float64}: Default: getdirichletUD(Uweights, 2, seed, bspolyparams)

• D_list::Vector{Float64}: Default: getdirichletUD(Dweights, 1, seed, bspolyparams)

• θ::Vector{Float64}: Default: getdirichletsamples(Ulist, Dlist, seed, weights, bspoly_params)

struct DirichletPDFParams <: AbstractPDFParams

Full Dirichlet specification of input PDF parameters.

Constructors:

• DirichletPDFParams(; fields...)

Fields:

• param_type::Int64: Default: DIRICHLET_TYPE

• θ::AbstractVector{T} where T<:Real

• K_u::Real

• λ_u::Real: Default: (θ[1] * (K_u + 1)) / (2 - θ[1])

• K_d::Real

• λ_d::Real: Default: (θ[2] * (K_d + 1)) / (1 - θ[2])

• λ_g1::Real

• λ_g2::Real

• K_g::Real

• λ_q::Real

• K_q::Real

QuarkCoefficients

Quark coefficients for structure function calculations.

struct ValencePDFParams <: AbstractPDFParams

Valence specification of input PDF parameters.

Constructors:

• ValencePDFParams(; fields...)

Fields:

• param_type::Int64: Default: VALENCE_TYPE

• λ_u::Real

• K_u::Real

• λ_d::Real

• K_d::Real

• λ_g1::Real

• λ_g2::Real

• K_g::Real

• λ_q::Real

• K_q::Real

• θ::AbstractVector{T} where T<:Real

Init_sys()

Reads various systematic errors and feeds them for further use

_fun_xsec_i(ix iq)

Input function for cross section spline. Must be wrapped for interface to SPLINT.

dd_xsecnc_xq2(charge, x_bin_cen, q2_bin_cen)

Double differential cross section for all x and q2 bins. NB: modifications needed to include pol and order.

dd_xsecnc_xq2_i(charge, x, q2)

Double differential cross section for single x and q2 values. NB: modifications needed to include pol and order.

f2_lo(x, q2)

Calculate the f2_lo structure function term. To be run after the evolution of PDFs with QCDNUM.

fl_lo(x, q2)

Calculate the fl_lo structure function term. To be run after the evolution of PDFs with QCDNUM.

forward_model(pdf_params, qcdnum_grid, 
              splint_params, quark_coeffs, sys_err_params)

Go from input PDF parameters to the expected number of events in bins.

forward_model_init(qcdnum_grid, qcdnum_params)

Initialise forward model. Initialises QCDNUM and builds weight tables to save time in subsequent iterations. Must be called prior to first instance of forward_model().

get_bin_info(n, quiet)

Get the bin egdes of the ZEUS detector space for a given bin number, n.

get_likelihood(pdf_params)

Get a suitable likelihood for a given PDF parametrisation.

get_prior(pdf_params)

Get a suitable prior for a given PDF parametrisation.

get_scaled_θ(λ_u, K_u, λ_d, K_d, θ_tmp)

Given a set of Dirichlet samples, θ_tmp, scale according to the valence params. Relevant for ValencePDFParams.

get_θ_val(rng, λ_u, K_u, λ_d, K_d, weights)

Given valance shape parameters and weights, get samples θ that are correctly scaled. Relevant for ValencePDFParams

Optional RNG parameter.

int_xtotx(pdf_params)

Total integrated momentum density. Should equal 1.

nc_propagator(q2, x)

pd_read_sim(file_name)

Read in the simulated truth and simulated data from HDF5 file.

pd_write_sim(file_name, pdf_params, sim_data)

Store the simulation truth and simulated data in an HDF5 file.

plot_data_space(pdf_params, sim_data, samples, qcdnum_grid, 
                qcdnum_params, splint_params, quark_coeffs)

Compare truth and posterior samples in the data space.

plot_model_space(pdf_params, samples)

Compare truth and posterior samples in the model space.

rxsecnc_xq2(x, q2)

Reduced cross section for all bins.

rxsecnc_xq2_i(charge, x, q2, F2, xF3, FL)

Reduced cross section for single x, q2.

x_dv_x(x, λ_d, K_d)

Momentum density of d valence component. Beta function Ad x^λd (1 - x)^Kd Ad is set by λd and Kd.

    x_g_x(x, λ_g1, λ_g2, K_g, K_q, w1, w2)

Momentum density of gluon component. Ag1 x^λg1 (1 - x)^Kg + Ag2 x^λg2 (1 - x)^Kq Amplitudes are set by weights w1 and w2.

x_q_x(x, λ_q, K_q, w)

Momentum density of non-valence quark component. Aq x^λq (1 - x)^K_q Amplitude is set by weight w

x_uv_x(x, λ_u, K_u)

Momentum density of u valence component. Beta function Au x^λu (1-x)^Ku Au is set by λu and Ku.

xf3_lo(x, q2)

Calculate the xf3_lo structure function term. To be run after the evolution of PDFs with QCDNUM.

x_total_x(x, pdf_params)

Total momentum density.