Add warmstart, model update, update docs

docs/cuopt/source/cuopt-python/lp-milp/lp-milp-api.rst

@@ -2,43 +2,44 @@
 LP and MILP API Reference
 =========================
 
-.. autoclass:: cuopt.linear_programming.problem.VType
+.. autoclass:: cuopt.linear_programming.problem.Problem
    :members:
-   :member-order: bysource
    :undoc-members:
-   :exclude-members: capitalize, casefold, center, count, encode, endswith, expandtabs, find, format, format_map, index, isalnum, isalpha, isascii, isdecimal, isdigit, isidentifier, islower, isnumeric, isprintable, isspace, istitle, isupper, join, ljust, lower, lstrip, maketrans, partition, removeprefix, removesuffix, replace, rfind, rindex, rjust, rpartition, rsplit, rstrip, split, splitlines, startswith, strip, swapcase, title, translate, upper, zfill
+   :exclude-members: reset_solved_values, populate_solution, dict_to_object, NumNZs, NumVariables, NumConstraints, IsMIP
 
-.. autoclass:: cuopt.linear_programming.problem.CType
+.. autoclass:: cuopt.linear_programming.problem.Variable
    :members:
-   :member-order: bysource
    :undoc-members:
-   :exclude-members: capitalize, casefold, center, count, encode, endswith, expandtabs, find, format, format_map, index, isalnum, isalpha, isascii, isdecimal, isdigit, isidentifier, islower, isnumeric, isprintable, isspace, istitle, isupper, join, ljust, lower, lstrip, maketrans, partition, removeprefix, removesuffix, replace, rfind, rindex, rjust, rpartition, rsplit, rstrip, split, splitlines, startswith, strip, swapcase, title, translate, upper, zfill
+   :exclude-members:
 
-.. autoclass:: cuopt.linear_programming.problem.sense
+.. autoclass:: cuopt.linear_programming.problem.LinearExpression
    :members:
-   :member-order: bysource
-   :exclude-members: __new__, __init__, _generate_next_value_, as_integer_ratio, bit_count, bit_length, conjugate, denominator, from_bytes, imag, is_integer, numerator, real, to_bytes
-   :no-inherited-members:
+   :undoc-members:
 
-.. autoclass:: cuopt.linear_programming.problem.Problem
+.. autoclass:: cuopt.linear_programming.problem.Constraint
+   :members:
+   :undoc-members:
+   :exclude-members: compute_slack
+
+.. autoclass:: cuopt.linear_programming.solver_settings.SolverSettings
    :members:
    :undoc-members:
-   :show-inheritance:
-   :exclude-members: reset_solved_values, post_solve, dict_to_object, NumNZs, NumVariables, NumConstraints, IsMIP
+   :exclude-members: to_base_type, toDict
 
-.. autoclass:: cuopt.linear_programming.problem.Variable
+.. autoclass:: cuopt.linear_programming.problem.VType
    :members:
+   :member-order: bysource
    :undoc-members:
-   :show-inheritance:
-   :exclude-members:
+   :exclude-members: capitalize, casefold, center, count, encode, endswith, expandtabs, find, format, format_map, index, isalnum, isalpha, isascii, isdecimal, isdigit, isidentifier, islower, isnumeric, isprintable, isspace, istitle, isupper, join, ljust, lower, lstrip, maketrans, partition, removeprefix, removesuffix, replace, rfind, rindex, rjust, rpartition, rsplit, rstrip, split, splitlines, startswith, strip, swapcase, title, translate, upper, zfill
 
-.. autoclass:: cuopt.linear_programming.problem.LinearExpression
+.. autoclass:: cuopt.linear_programming.problem.CType
    :members:
+   :member-order: bysource
    :undoc-members:
-   :show-inheritance:
+   :exclude-members: capitalize, casefold, center, count, encode, endswith, expandtabs, find, format, format_map, index, isalnum, isalpha, isascii, isdecimal, isdigit, isidentifier, islower, isnumeric, isprintable, isspace, istitle, isupper, join, ljust, lower, lstrip, maketrans, partition, removeprefix, removesuffix, replace, rfind, rindex, rjust, rpartition, rsplit, rstrip, split, splitlines, startswith, strip, swapcase, title, translate, upper, zfill
 
-.. autoclass:: cuopt.linear_programming.problem.Constraint
+.. autoclass:: cuopt.linear_programming.problem.sense
    :members:
+   :member-order: bysource
    :undoc-members:
-   :show-inheritance:
-   :exclude-members: compute_slack
+   :exclude-members: __new__, __init__, _generate_next_value_, as_integer_ratio, bit_count, bit_length, conjugate, denominator, from_bytes, imag, is_integer, numerator, real, to_bytes

docs/cuopt/source/cuopt-python/lp-milp/lp-milp-examples.rst

@@ -309,3 +309,78 @@ The response is as follows:
     Solve time: 0.16 seconds
     Final solution: x=36.0, y=40.99999999999999
     Final objective value: 303.00
+
+Working with PDLP Warmstart Data
+--------------------------------
+
+Warmstart data allows to restart PDLP with a previous solution context. This should be used when you solve a new problem which is similar to the previous one.
+
+.. note::
+    Warmstart data is only available for Linear Programming (LP) problems, not for Mixed Integer Linear Programming (MILP) problems.
+
+.. code-block:: python
+
+    from cuopt.linear_programming.problem import Problem, CONTINUOUS, MAXIMIZE
+    from cuopt.linear_programming.solver.solver_parameters import CUOPT_METHOD
+    from cuopt.linear_programming.solver_settings import SolverSettings, SolverMethod
+
+    # Create a new problem
+    problem = Problem("Simple LP")
+
+    # Add variables
+    x = problem.addVariable(lb=0, vtype=CONTINUOUS, name="x")
+    y = problem.addVariable(lb=0, vtype=CONTINUOUS, name="y")
+
+    # Add constraints
+    problem.addConstraint(4*x + 10*y <= 130, name="c1")
+    problem.addConstraint(8*x - 3*y >= 40, name="c2")
+
+    # Set objective function
+    problem.setObjective(2*x + y, sense=MAXIMIZE)
+
+    # Configure solver settings
+    settings = SolverSettings()
+    settings.set_parameter(CUOPT_METHOD, SolverMethod.PDLP)
+
+    # Solve the problem
+    problem.solve(settings)
+
+    # Get the warmstart data
+    warmstart_data = problem.get_pdlp_warm_start_data()
+
+    print(warmstart_data.current_primal_solution)
+    # Create a new problem
+    new_problem = Problem("Warmstart LP")
+
+    # Add variables
+    x = new_problem.addVariable(lb=0, vtype=CONTINUOUS, name="x")
+    y = new_problem.addVariable(lb=0, vtype=CONTINUOUS, name="y")
+
+    # Add constraints
+    new_problem.addConstraint(4*x + 10*y <= 100, name="c1")
+    new_problem.addConstraint(8*x - 3*y >= 50, name="c2")
+
+    # Set objective function
+    new_problem.setObjective(2*x + y, sense=MAXIMIZE)
+
+    # Configure solver settings
+    settings.set_pdlp_warm_start_data(warmstart_data)
+
+    # Solve the problem
+    new_problem.solve(settings)
+
+    # Check solution status
+    if new_problem.Status.name == "Optimal":
+        print(f"Optimal solution found in {new_problem.SolveTime:.2f} seconds")
+        print(f"x = {x.getValue()}")
+        print(f"y = {y.getValue()}")
+        print(f"Objective value = {new_problem.ObjValue}")
+
+The response is as follows:
+
+.. code-block:: text
+
+    Optimal solution found in 0.01 seconds
+    x = 25.000000000639382
+    y = 0.0
+    Objective value = 50.000000001278764