$title Stigler's Nutrition Model (DIET,SEQ=7)

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This model determines a least cost diet which meets the daily
allowances of nutrients for a moderately active man weighing 154 lbs.

Dantzig, G B, Chapter 27.1. In Linear Programming and Extensions.
Princeton University Press, Princeton, New Jersey, 1963.

Keywords: linear programming, diet problem, Stigler diet, minimum cost diet
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Set
   n 'nutrients' / calorie    'thousands',  protein   'grams',        calcium    'grams'
                   iron       'milligrams', vitamin-a 'thousand ius', vitamin-b1 'milligrams'
                   vitamin-b2 'milligrams', niacin    'milligrams'  , vitamin-c  'milligrams' /

   f 'foods'     / wheat  , cornmeal , cannedmilk, margarine , cheese   , peanut-b , lard
                   liver  , porkroast, salmon    , greenbeans, cabbage  , onions   , potatoes
                   spinach, sweet-pot, peaches   , prunes    , limabeans, navybeans           /;

Parameter b(n) 'required daily allowances of nutrients'
               / calorie     3,   protein   70, calcium      .8
                 iron       12,   vitamin-a  5, vitamin-b1  1.8
                 vitamin-b2  2.7, niacin    18, vitamin-c  75   /;

Table a(f,n) 'nutritive value of foods (per dollar spent)'
                calorie  protein  calcium  iron  vitamin-a  vitamin-b1  vitamin-b2  niacin  vitamin-c
*                (1000)      (g)      (g)  (mg)    1000iu)        (mg)        (mg)    (mg)       (mg)
   wheat           44.7     1411      2.0   365                   55.4        33.3     441
   cornmeal        36        897      1.7    99       30.9        17.4         7.9     106
   cannedmilk       8.4      422     15.1     9       26           3          23.5      11         60
   margarine       20.6       17       .6     6       55.8          .2
   cheese           7.4      448     16.4    19       28.1          .8        10.3       4
   peanut-b        15.7      661      1      48                    9.6         8.1     471
   lard            41.7                                 .2                      .5       5
   liver            2.2      333       .2   139      169.2         6.4        50.8     316        525
   porkroast        4.4      249       .3    37                   18.2         3.6      79
   salmon           5.8      705      6.8    45        3.5         1           4.9     209
   greenbeans       2.4      138      3.7    80       69           4.3         5.8      37        862
   cabbage          2.6      125      4      36        7.2         9           4.5      26       5369
   onions           5.8      166      3.8    59       16.6         4.7         5.9      21       1184
   potatoes        14.3      336      1.8   118        6.7        29.4         7.1     198       2522
   spinach          1.1      106            138      918.4         5.7        13.8      33       2755
   sweet-pot        9.6      138      2.7    54      290.7         8.4         5.4      83       1912
   peaches          8.5       87      1.7   173       86.8         1.2         4.3      55         57
   prunes          12.8       99      2.5   154       85.7         3.9         4.3      65        257
   limabeans       17.4     1055      3.7   459        5.1        26.9        38.2      93
   navybeans       26.9     1691     11.4   792                   38.4        24.6     217           ;

Positive Variable x(f) 'dollars of food f to be purchased daily (dollars)';

Free Variable cost 'total food bill (dollars)';

Equation
   nb(n) 'nutrient balance (units)'
   cb    'cost balance   (dollars)';

nb(n).. sum(f, a(f,n)*x(f)) =g= b(n);

cb..    cost =e= sum(f, x(f));

Model diet 'stiglers diet problem' / nb, cb /;

solve diet minimizing cost using lp;