Error during computation of PTDF matrix with dist_slack

[alefcastelli]

When executing the following code:

using PowerNetworkMatrices
using PowerSystemCaseBuilder

const PNM = PowerNetworkMatrices
const PSB = PowerSystemCaseBuilder

sys = PSB.build_system(PSB.PSITestSystems, "c_sys5");

ba_matrix = BA_Matrix(sys);
buses = PNM.get_ac_branches(sys);

# get bus and slack numbers
bus_number = length(buses);
ref_bus_number = length(ba_matrix.ref_bus_positions);

# define dist_slack vector
dist_slack_values = 1/bus_n*ones(bus_number-ref_bus_number);

# compute PTDF matrix with distributed slack buses
ptdf_6 = PTDF(sys, dist_slack=dist_slack_values)

This error is thrown:

ERROR: ArgumentError: invalid index: Set([4]) of type Set{Int64}
Stacktrace:
  [1] to_index(i::Set{Int64})
    @ Base ./indices.jl:300
  [2] to_index(A::Matrix{Float64}, i::Set{Int64})
    @ Base ./indices.jl:277
  [3] to_indices
    @ ./indices.jl:333 [inlined]
  [4] to_indices
    @ ./indices.jl:324 [inlined]
  [5] view
    @ ./subarray.jl:176 [inlined]
  [6] maybeview
    @ ./views.jl:146 [inlined]
  [7] dotview
    @ ./broadcast.jl:1201 [inlined]
  [8] _calculate_PTDF_matrix_KLU(A::SparseArrays.SparseMatrixCSC{Int8, Int64}, BA::SparseArrays.SparseMatrixCSC{Float64, Int64}, ref_bus_positions::Set{Int64}, dist_slack::Vector{Float64})
    @ PowerNetworkMatrices ~/Documents/GitHub/PowerNetworkMatrices.jl/src/ptdf_calculations.jl:156
  [9] calculate_PTDF_matrix_KLU
    @ ~/Documents/GitHub/PowerNetworkMatrices.jl/src/ptdf_calculations.jl:185 [inlined]
 [10] _buildptdf(branches::Vector{PowerSystems.ACBranch}, buses::Vector{PowerSystems.Bus}, bus_lookup::Dict{Int64, Int64}, dist_slack::Vector{Float64}, linear_solver::String)
    @ PowerNetworkMatrices ~/Documents/GitHub/PowerNetworkMatrices.jl/src/ptdf_calculations.jl:67
 [11] PTDF(branches::Vector{PowerSystems.ACBranch}, buses::Vector{PowerSystems.Bus}; dist_slack::Vector{Float64}, linear_solver::String, tol::Float64)
    @ PowerNetworkMatrices ~/Documents/GitHub/PowerNetworkMatrices.jl/src/ptdf_calculations.jl:402
 [12] #PTDF#33
    @ ~/Documents/GitHub/PowerNetworkMatrices.jl/src/ptdf_calculations.jl:435 [inlined]

Solution to this error is to change Line 156 in ptdf_calculation.jl with the following line: PTDFm_t[collect(ref_bus_positions), :] .= 0.0