rewrite rcpsp_sat example

This commit is contained in:
Laurent Perron
2021-06-29 17:20:38 +02:00
parent 1c2519dff5
commit 072938b720
3 changed files with 114 additions and 116 deletions

View File

@@ -109,104 +109,90 @@ def SolveRcpsp(problem, proto_file, params):
horizon += abs(d)
print(f' - horizon = {horizon}')
# Containers used to build resources.
intervals_per_resource = collections.defaultdict(list)
demands_per_resource = collections.defaultdict(list)
presences_per_resource = collections.defaultdict(list)
starts_per_resource = collections.defaultdict(list)
# Starts and ends for each task (shared between all alternatives)
# Containers.
task_starts = {}
task_ends = {}
task_durations = {}
task_intervals = {}
task_to_resource_demands = collections.defaultdict(list)
# Containers for per-recipe per task alternatives variables.
presences_per_task = collections.defaultdict(list)
durations_per_task = collections.defaultdict(list)
task_to_presence_literals = collections.defaultdict(list)
task_to_recipe_durations = collections.defaultdict(list)
task_resource_to_fixed_demands = collections.defaultdict(dict)
one = model.NewConstant(1)
resource_to_sum_of_demand_max = collections.defaultdict(int)
# Create tasks variables.
# Create task variables.
for t in all_active_tasks:
task = problem.tasks[t]
num_recipes = len(task.recipes)
all_recipes = range(num_recipes)
if len(task.recipes) == 1:
# Create main and unique interval.
recipe = task.recipes[0]
task_starts[t] = model.NewIntVar(0, horizon, f'start_of_task_{t}')
task_ends[t] = model.NewIntVar(0, horizon, f'end_of_task_{t}')
interval = model.NewIntervalVar(task_starts[t], recipe.duration,
task_ends[t], f'interval_{t}')
start_var = model.NewIntVar(0, horizon, f'start_of_task_{t}')
end_var = model.NewIntVar(0, horizon, f'end_of_task_{t}')
# Store as a single alternative for later.
presences_per_task[t].append(one)
durations_per_task[t].append(recipe.duration)
# Create one literal per recipe.
literals = [
model.NewBoolVar(f'is_present_{t}_{r}') for r in all_recipes
]
# Register the interval in resources specified by the demands.
for i in range(len(recipe.demands)):
demand = recipe.demands[i]
res = recipe.resources[i]
demands_per_resource[res].append(demand)
if problem.resources[res].renewable:
intervals_per_resource[res].append(interval)
else:
starts_per_resource[res].append(task_starts[t])
presences_per_resource[res].append(1)
else: # Multiple alternative recipes.
all_recipes = range(len(task.recipes))
# Exactly one recipe must be performed.
model.Add(cp_model.LinearExpr.Sum(literals) == 1)
start = model.NewIntVar(0, horizon, f'start_of_task_{t}')
end = model.NewIntVar(0, horizon, f'end_of_task_{t}')
# Temporary data structure to fill in 0 demands.
demand_matrix = collections.defaultdict(int)
# Store for precedences.
task_starts[t] = start
task_ends[t] = end
# Scan recipes and build the demand matrix and the vector of durations.
for recipe_index, recipe in enumerate(task.recipes):
task_to_recipe_durations[t].append(recipe.duration)
for demand, resource in zip(recipe.demands, recipe.resources):
demand_matrix[(resource, recipe_index)] = demand
# Create one optional interval per recipe.
for r in all_recipes:
recipe = task.recipes[r]
is_present = model.NewBoolVar(f'is_present_{t}_{r}')
interval = model.NewOptionalIntervalVar(start, recipe.duration,
end, is_present,
f'interval_{t}_{r}')
# Create the duration variable from the accumulated durations.
duration_var = model.NewIntVarFromDomain(
cp_model.Domain.FromValues(task_to_recipe_durations[t]),
f'duration_of_task_{t}')
# Store alternative variables.
presences_per_task[t].append(is_present)
durations_per_task[t].append(recipe.duration)
# linear encoding of the duration (link recipe literals and duration).
min_duration = min(task_to_recipe_durations[t])
shifted = [x - min_duration for x in task_to_recipe_durations[t]]
model.Add(duration_var == min_duration +
cp_model.LinearExpr.ScalProd(literals, shifted))
# Register the interval in resources specified by the demands.
for i in range(len(recipe.demands)):
demand = recipe.demands[i]
res = recipe.resources[i]
demands_per_resource[res].append(demand)
if problem.resources[res].renewable:
intervals_per_resource[res].append(interval)
else:
starts_per_resource[res].append(start)
presences_per_resource[res].append(is_present)
# Create the interval of the task.
task_interval = model.NewIntervalVar(start_var, duration_var, end_var,
f'task_interval_{t}')
# Exactly one alternative must be performed.
model.Add(sum(presences_per_task[t]) == 1)
# Store task variables.
task_starts[t] = start_var
task_ends[t] = end_var
task_durations[t] = duration_var
task_intervals[t] = task_interval
task_to_presence_literals[t] = literals
# linear encoding of the duration.
min_duration = min(durations_per_task[t])
max_duration = max(durations_per_task[t])
shifted = [x - min_duration for x in durations_per_task[t]]
# Create the demand variable of the task for each resource.
for resource in all_resources:
demands = [
demand_matrix[(resource, recipe)] for recipe in all_recipes
]
task_resource_to_fixed_demands[(t, resource)] = demands
demand_var = model.NewIntVarFromDomain(
cp_model.Domain.FromValues(demands), f'demand_{t}_{resource}')
task_to_resource_demands[t].append(demand_var)
duration = model.NewIntVar(min_duration, max_duration,
f'duration_of_task_{t}')
model.Add(
duration == min_duration +
cp_model.LinearExpr.ScalProd(presences_per_task[t], shifted))
# We do not create a 'main' interval. Instead, we link start, end, and
# duration.
model.Add(start + duration == end)
# linear encoding of the demand per resource.
min_demand = min(demands)
shifted = [x - min_demand for x in demands]
model.Add(demand_var == min_demand +
cp_model.LinearExpr.ScalProd(literals, shifted))
resource_to_sum_of_demand_max[resource] += max(demands)
# Create makespan variable
makespan = model.NewIntVar(0, horizon, 'makespan')
interval_makespan = model.NewIntervalVar(
makespan, model.NewIntVar(1, horizon, 'interval_makespan_size'),
model.NewConstant(horizon + 1), 'interval_makespan')
makespan_size = model.NewIntVar(1, horizon, 'interval_makespan_size')
interval_makespan = model.NewIntervalVar(makespan, makespan_size,
model.NewConstant(horizon + 1),
'interval_makespan')
# Add precedences.
if problem.is_rcpsp_max:
@@ -222,7 +208,7 @@ def SolveRcpsp(problem, proto_file, params):
num_next_modes = len(problem.tasks[next_id].recipes)
for m1 in range(num_modes):
s1 = task_starts[task_id]
p1 = presences_per_task[task_id][m1]
p1 = task_to_presence_literals[task_id][m1]
if next_id == num_tasks - 1:
delay = delay_matrix.recipe_delays[m1].min_delays[0]
model.Add(s1 + delay <= makespan).OnlyEnforceIf(p1)
@@ -231,7 +217,7 @@ def SolveRcpsp(problem, proto_file, params):
delay = delay_matrix.recipe_delays[m1].min_delays[
m2]
s2 = task_starts[next_id]
p2 = presences_per_task[next_id][m2]
p2 = task_to_presence_literals[next_id][m2]
model.Add(s1 + delay <= s2).OnlyEnforceIf([p1, p2])
else:
# Normal dependencies (task ends before the start of successors).
@@ -251,35 +237,57 @@ def SolveRcpsp(problem, proto_file, params):
resource = problem.resources[r]
c = resource.max_capacity
if c == -1:
c = sum(demands_per_resource[r])
print(f'No capacity: {resource}')
c = resource_to_sum_of_demand_max[r]
# RIP problems have only renewable resources, and no makespan.
if problem.is_resource_investment or resource.renewable:
intervals = [task_intervals[t] for t in all_active_tasks]
demands = [task_to_resource_demands[t][r] for t in all_active_tasks]
if problem.is_resource_investment:
capacity = model.NewIntVar(0, c, f'capacity_of_{r}')
model.AddCumulative(intervals, demands, capacity)
capacities.append(capacity)
max_cost += c * resource.unit_cost
else: # Standard renewable resource.
energies = []
for t in all_active_tasks:
literals = task_to_presence_literals[t]
fixed_energies = [
task_resource_to_fixed_demands[(t, r)][index] *
task_to_recipe_durations[t][index]
for index in range(len(literals))
]
min_energy = min(fixed_energies)
scaled_energies = [x - min_energy for x in fixed_energies]
energies.append(
min_energy +
cp_model.LinearExpr.ScalProd(literals, scaled_energies))
if problem.is_resource_investment:
# RIP problems have only renewable resources.
capacity = model.NewIntVar(0, c, f'capacity_of_{r}')
model.AddCumulative(intervals_per_resource[r],
demands_per_resource[r], capacity)
capacities.append(capacity)
max_cost += c * resource.unit_cost
elif resource.renewable:
if intervals_per_resource[r]:
if FLAGS.use_interval_makespan:
model.AddCumulative(
intervals_per_resource[r] + [interval_makespan],
demands_per_resource[r] + [c], c)
else:
model.AddCumulative(intervals_per_resource[r],
demands_per_resource[r], c)
elif presences_per_resource[r]: # Non empty non renewable resource.
intervals.append(interval_makespan)
demands.append(c)
energies.append(c * makespan_size)
model.AddCumulativeWithEnergy(intervals, demands, energies, c)
else: # Non empty non renewable resource. (single mode only)
if problem.is_consumer_producer:
model.AddReservoirConstraint(starts_per_resource[r],
demands_per_resource[r],
reservoir_starts = []
reservoir_demands = []
for t in all_active_tasks:
if task_resource_to_fixed_demands[(t, r)][0]:
reservoir_starts.append(task_starts[t])
reservoir_demands.append(
task_resource_to_fixed_demands[(t, r)][0])
model.AddReservoirConstraint(reservoir_starts,
reservoir_demands,
resource.min_capacity,
resource.max_capacity)
else:
else: # No producer-consumer. We just sum the demands.
model.Add(
sum(presences_per_resource[r][i] *
demands_per_resource[r][i]
for i in range(len(presences_per_resource[r]))) <= c)
cp_model.LinearExpr.Sum([
task_to_resource_demands[t][r] for t in all_active_tasks
]) <= c)
# Objective.
if problem.is_resource_investment: