{"id":775,"date":"2016-08-03T09:10:25","date_gmt":"2016-08-03T07:10:25","guid":{"rendered":"http:\/\/www.supagro.fr\/wordpress\/modeleco\/?page_id=775"},"modified":"2024-05-30T14:04:38","modified_gmt":"2024-05-30T12:04:38","slug":"approvisionnement-des-villes","status":"publish","type":"page","link":"https:\/\/www.supagro.fr\/wordpress\/modelecoen\/auto-formation\/sequence1\/cours2-introduction-a-gams\/qq-exercices-supplementaires\/approvisionnement-des-villes\/","title":{"rendered":"Adding a constraint to the wheat\/maize model"},"content":{"rendered":"

Dur\u00e9e : environ 15 minutes<\/span><\/h4>\n

Download the model\u00a0primal1.zip<\/a>. Once you have unzipped it and saved it under another name (for example primal1_approvisionnement.gms), run it using GAMS-IDE. Modify the model in order to add the constraint imposed by the government.<\/p>\n

\u00a0<\/em>\u00ab\u00a0A given farm can grow two types of crop : wheat and maize. The area to be cultivated must be determined for each crop, knowing that :
\nThe objective of the farmer is to maximize his income.
\nWheat yields 450\u20ac per hectare, maize 1000\u20ac.
\nWheat requires 25 hours of labour per hectare and per year, and maize 50 hours.<\/p>\n

The farm area is 50 ha and the farmer can work 2000 hours a year.<\/em>
\nLet us imagine that in order to ensure food supplies for cities, the government requires that every farmer cultivate at least 80 ha of cereal crops.<\/em>\u00a0<\/em>\u00bb<\/p>\n

Once you have run the new model, answer the questions !<\/strong><\/p>\n