Overconstrained Error emerging from measure.cumulative_resource()

[elliott-huge]

Code to reproduce error:

from mat_dp_core import Resources, Processes, GeConstraint, LeConstraint, Measure

r = Resources()
iron_ore = r.create("Iron Ore", "metric tonnes")
iron = r.create("Iron", "metric tonnes")
coal = r.create("Coal", "metric tonnes")
carbon_dioxide = r.create("CO2", "metric tonnes")
steel = r.create("Steel", "metric tonnes")
rail = r.create("Steel Rail", "metres")
wagon = r.create("Railway Wagon", "units")

p = Processes()
coal_mine = p.create("Coal Mine", (carbon_dioxide, 0.2), (coal, 1.0))
iron_mine = p.create("Iron Ore Mine", (carbon_dioxide, 0.2), (iron_ore, 1.0))
iron_furnace = p.create("Iron Blast Furnace", (carbon_dioxide, 0.5), (iron, 1.0), (coal, -0.4), (iron_ore, -1.2))
steel_mill = p.create("Steel Mill", (carbon_dioxide, 0.7), (iron, -0.9), (coal, -0.5), (steel, 1.0))
rail_factory = p.create("Rail Manufacturing Factory", (carbon_dioxide, 0.1), (steel, -0.1), (rail, 1.0))
rail_wagon_factory = p.create("Wagon Manufacturing Factory", (carbon_dioxide, 0.3), (steel, -4.0), (wagon, 1.0))
environment = p.create("The Atmosphere", (carbon_dioxide, -1.0))

rail_buy = p.create("Economy demanding rail", (rail, -1))
wagon_buy = p.create("Economy demanding wagons", (wagon, -1))

# Constraints
rail_demand = GeConstraint("Demand for rail", rail_buy, 500)
wagon_demand = GeConstraint("Demand for wagons", wagon_buy, 5)

objective = environment

constraints = [rail_demand, wagon_demand]

measure = Measure(r, p, constraints, objective)

# .cumulative_resource()

# This example of cumulative_resource() is not yet operational
# See issue NUMBER_HERE for details.
print("---\n\n1) All cumulative resource flows from everything to everything:")
# print(measure.cumulative_resource()) # Option 1

print("---\n\n2) All cumulative resource flows from everything to the wagon factory:")
print(measure.cumulative_resource(process=rail_wagon_factory)) # Option 2

print("---\n\n3) Cumulative resource flows of iron from everything to everything::")
print(measure.cumulative_resource(resource=iron)) # Option 3

print("---\n\n4) Cumulative amount of CO2 leading up to all the production rail factory:")
print(measure.cumulative_resource(process=rail_factory, resource=carbon_dioxide)) # Option 4

Produces the following error:

PS ######\mat-dp-core\examples> poetry run python .\test.py
---

1) All cumulative resource flows from everything to everything:
---

2) All cumulative resource flows from everything to the wagon factory:
######\mat-dp-core\mat_dp_core\maths_core\solve.py:201: OptimizeWarning: A_eq does not appear to be of full row rank. To improve performance, check the problem formulation for redundant equality constraints.
  res = linprog(
Traceback (most recent call last):
  File "######\mat-dp-core\examples\test.py", line 255, in <module>
    print(measure.cumulative_resource(process=rail_wagon_factory)) # Option 2
  File "######\mat-dp-core\mat_dp_core\measure.py", line 758, in cumulative_resource
    self.cumulative_resource_matrix[:, process.index],
  File "######\mat-dp-core\mat_dp_core\maths_core\solvers.py", line 386, in cumulative_resource_matrix
    self._exact_solver.cumulative_resource_matrix
  File "######\mat-dp-core\mat_dp_core\maths_core\solvers.py", line 214, in cumulative_resource_matrix
    construct_cumulative_resource_matrix(
  File "######\mat-dp-core\mat_dp_core\maths_core\solvers.py", line 134, in construct_cumulative_resource_matrix
    [
  File "######\mat-dp-core\mat_dp_core\maths_core\solvers.py", line 135, in <listcomp>
    solve(
  File "######\mat-dp-core\mat_dp_core\maths_core\solve.py", line 237, in solve
    raise Overconstrained.from_vector(
mat_dp_core.maths_core.exceptions.Overconstrained: Overconstrained problem:
resources:
Coal => 60.200000007230194: increase runs of Iron Blast Furnace, Steel Mill or decrease runs of Coal Mine
CO2 => 12.040000001446039: increase runs of The Atmosphere or decrease runs of Coal Mine, Iron Ore Mine, Iron Blast Furnace, Steel Mill, Rail Manufacturing Factory, Wagon Manufacturing Factory
eq_constraints:
Coal Mine - 1.255813953488226*Iron Ore Mine == 0 => -60.200000007230194
Coal Mine - 1.0465116279069493*Iron Blast Furnace == 0 => -60.200000007230194
Coal Mine - 1.1627906976743299*Steel Mill == 0 => -60.200000007230194
Coal Mine - 8.305647840271908*Rail Manufacturing Factory == 0 => -60.200000007230194
Coal Mine - 0.0830564784122155*Wagon Manufacturing Factory == 0 => -60.200000007230194
PS ######\mat-dp-core\examples>