gams:compute_the_median_of_a_parameter_s_values

The code fragment below was contributed by Tom Rutherford to theGAMS User List, an example for multidimensional data is available on his web site mpsge.org.

$title Finding the Median of a Distribution in GAMS set i Individuals /i1*i1000/; alias (i,j); parameter income(i) Personal income, rank(i) Income rank, median Median income; * Make it random for the purpose of illustration: income(i) = uniform(0,1); * This is ugly and slow, but it works: rank(i) = sum(j$(income(j) gt income(i)), 1) + 1; * In this example there will be no ties, there could be a tie in an arbitrary * application. Just to be safe, divide through by the number of * median individuals: median = sum(i$(rank(i) eq round(card(i)/2)), income(i)) / sum(i$(rank(i) eq round(card(i)/2)), 1); display median;

gams/compute_the_median_of_a_parameter_s_values.txt · Last modified: 2009/05/29 10:52 by support