diff --git a/content/Week_2_5/WS_2_5_Profit_vs_Planet.ipynb b/content/Week_2_5/WS_2_5_Profit_vs_Planet.ipynb
index 4f78ce11bf161fc669c36f3f306e136051b15a84..7d05bc65bedc3715fb300bed4d4733891e07ca01 100644
--- a/content/Week_2_5/WS_2_5_Profit_vs_Planet.ipynb
+++ b/content/Week_2_5/WS_2_5_Profit_vs_Planet.ipynb
@@ -203,7 +203,7 @@
"\n",
"Solve the model with an additional constraint: if project 1 is done then the impact of all projects together should be lower than $\\gamma$ with $\\gamma=130$.\n",
"\n",
- "In the first cell you should add the constraint, then in a second cell optimize the model.\n",
+ "Paste your model previous model, and call it <code>model2</code> to keep the results separated and add the new constraint. Then run your second model. \n",
"\n",
"</p>\n",
"</div>"
@@ -219,16 +219,6 @@
"YOUR_CODE_HERE"
]
},
- {
- "cell_type": "code",
- "execution_count": null,
- "id": "19040bd6",
- "metadata": {},
- "outputs": [],
- "source": [
- "YOUR_CODE_HERE"
- ]
- },
{
"cell_type": "markdown",
"id": "603aea77",
diff --git a/content/Week_2_5/WS_2_5_solution.ipynb b/content/Week_2_5/WS_2_5_solution.ipynb
index 41c670cafc58ce05882d2a590d5b7d5f42b35dd8..5020acc6dab9936e442d40781fc5b4c577fc3966 100644
--- a/content/Week_2_5/WS_2_5_solution.ipynb
+++ b/content/Week_2_5/WS_2_5_solution.ipynb
@@ -127,7 +127,7 @@
},
{
"cell_type": "code",
- "execution_count": 2,
+ "execution_count": 8,
"id": "d5cba9fe",
"metadata": {},
"outputs": [],
@@ -209,7 +209,7 @@
},
{
"cell_type": "code",
- "execution_count": 3,
+ "execution_count": 9,
"id": "8d008ba9",
"metadata": {},
"outputs": [
@@ -217,9 +217,6 @@
"name": "stdout",
"output_type": "stream",
"text": [
- "Set parameter Username\n",
- "Set parameter LicenseID to value 2588551\n",
- "Academic license - for non-commercial use only - expires 2025-11-21\n",
"Gurobi Optimizer version 12.0.0 build v12.0.0rc1 (win64 - Windows 11.0 (22631.2))\n",
"\n",
"CPU model: 13th Gen Intel(R) Core(TM) i7-1365U, instruction set [SSE2|AVX|AVX2]\n",
@@ -233,7 +230,7 @@
" Objective range [5e+01, 1e+02]\n",
" Bounds range [1e+00, 1e+00]\n",
" RHS range [3e+00, 3e+02]\n",
- "Presolve time: 0.01s\n",
+ "Presolve time: 0.00s\n",
"Presolved: 3 rows, 6 columns, 17 nonzeros\n",
"Variable types: 0 continuous, 6 integer (6 binary)\n",
"Found heuristic solution: objective 228.0000000\n",
@@ -246,7 +243,7 @@
"\n",
" 0 0 cutoff 0 198.00000 198.00000 0.00% - 0s\n",
"\n",
- "Explored 1 nodes (3 simplex iterations) in 0.04 seconds (0.00 work units)\n",
+ "Explored 1 nodes (3 simplex iterations) in 0.03 seconds (0.00 work units)\n",
"Thread count was 12 (of 12 available processors)\n",
"\n",
"Solution count 2: 198 228 \n",
@@ -289,7 +286,7 @@
},
{
"cell_type": "code",
- "execution_count": 4,
+ "execution_count": 10,
"id": "83ef8b18",
"metadata": {},
"outputs": [
@@ -318,7 +315,7 @@
"name": "stderr",
"output_type": "stream",
"text": [
- "C:\\Users\\jdding\\AppData\\Local\\Temp\\ipykernel_6080\\2324086517.py:6: DeprecationWarning: Model.display() is deprecated\n",
+ "C:\\Users\\jdding\\AppData\\Local\\Temp\\ipykernel_17648\\2324086517.py:6: DeprecationWarning: Model.display() is deprecated\n",
" model.display()\n"
]
}
@@ -345,7 +342,7 @@
},
{
"cell_type": "markdown",
- "id": "98cb6023",
+ "id": "e93fc43f",
"metadata": {},
"source": [
"<div style=\"background-color:#AABAB2; color: black; vertical-align: middle; padding:15px; margin: 10px; border-radius: 10px; width: 95%\">\n",
@@ -354,7 +351,7 @@
"\n",
"Solve the model with an additional constraint: if project 1 is done then the impact of all projects together should be lower than $\\gamma$ with $\\gamma=130$.\n",
"\n",
- "In the first cell you should add the constraint, then in a second cell optimize the model.\n",
+ "Paste your model previous model, and call it <code>model2</code> to keep the results separated and add the new constraint. Then run your second model. \n",
"\n",
"</p>\n",
"</div>"
@@ -362,7 +359,7 @@
},
{
"cell_type": "code",
- "execution_count": 5,
+ "execution_count": 11,
"id": "9f2f9b6d",
"metadata": {},
"outputs": [
@@ -372,7 +369,7 @@
"<gurobi.Constr *Awaiting Model Update*>"
]
},
- "execution_count": 5,
+ "execution_count": 11,
"metadata": {},
"output_type": "execute_result"
}
@@ -381,15 +378,26 @@
"# YOUR_CODE_HERE\n",
"\n",
"# SOLUTION\n",
+ "model2 = gp.Model(\"Project_Selection\")\n",
+ "x = model2.addVars(num_projects, vtype=gp.GRB.BINARY, name=\"x\")\n",
+ "model2.setObjective(sum(I[i] * x[i] for i in range(num_projects)),\n",
+ " gp.GRB.MINIMIZE)\n",
+ "model2.addConstr(x.sum() == 3, \"Select_Projects\")\n",
+ "model2.addConstr((sum(x[i] for i in range(num_type2_projects, num_projects))\n",
+ " - sum(x[i] for i in range(num_type1_projects)) >= 0),\n",
+ " \"Type_Constraint\")\n",
+ "model2.addConstr(sum(P[i] * x[i] for i in range(num_projects)) >= beta,\n",
+ " \"Minimum_Profit\")\n",
"gamma = 130\n",
- "model.addConstr((sum(I[i] * x[i] for i in range(num_projects))\n",
+ "model2.addConstr((sum(I[i] * x[i] for i in range(num_projects))\n",
" <= gamma * x[0]+ M * (1 - x[0])),\n",
- " \"Impact_Constraint\") "
+ " \"Impact_Constraint\") \n",
+ "\n"
]
},
{
"cell_type": "code",
- "execution_count": 6,
+ "execution_count": 12,
"id": "19040bd6",
"metadata": {},
"outputs": [
@@ -410,10 +418,6 @@
" Objective range [5e+01, 1e+02]\n",
" Bounds range [1e+00, 1e+00]\n",
" RHS range [3e+00, 1e+05]\n",
- "\n",
- "MIP start from previous solve did not produce a new incumbent solution\n",
- "MIP start from previous solve violates constraint Impact_Constraint by 68.000000000\n",
- "\n",
"Presolve removed 4 rows and 6 columns\n",
"Presolve time: 0.00s\n",
"Presolve: All rows and columns removed\n",
@@ -448,8 +452,8 @@
"name": "stderr",
"output_type": "stream",
"text": [
- "C:\\Users\\jdding\\AppData\\Local\\Temp\\ipykernel_6080\\1357951651.py:8: DeprecationWarning: Model.display() is deprecated\n",
- " model.display()\n"
+ "C:\\Users\\jdding\\AppData\\Local\\Temp\\ipykernel_17648\\2231829295.py:8: DeprecationWarning: Model.display() is deprecated\n",
+ " model2.display()\n"
]
}
],
@@ -457,14 +461,14 @@
"# YOUR_CODE_HERE\n",
"\n",
"# SOLUTION\n",
- "model.optimize()\n",
+ "model2.optimize()\n",
"\n",
"print(\"Model structure:\") \n",
"# see the model that you have built in a nice why to interpret\n",
- "model.display() \n",
+ "model2.display() \n",
"\n",
"# Display the solution\n",
- "if model.status == gp.GRB.OPTIMAL:\n",
+ "if model2.status == gp.GRB.OPTIMAL:\n",
" print(\"Optimal Solution:\")\n",
" for i in range(num_projects):\n",
" if x[i].x > 0.9:\n",
@@ -473,7 +477,7 @@
" print(\"No optimal solution found.\")\n",
"\n",
" \n",
- "print(\"Optimal Objective function Value\", model.objVal) "
+ "print(\"Optimal Objective function Value\", model2.objVal) "
]
},
{