Originally posted by: Calvin Sun Hainan

How to find the mode for the following list of values in OPL:

{int} array = {13, 18, 13, 14, 13, 16, 14, 21, 13}

The "mode" is the value that occurs most often.

I need something like mode(array) to return me 13 in this case. Is there an easy way to do in OPL? It is very easy to do min or max, but it seems that mode is not so straightforward. It seems that I have to write OPL script to find mode.

Hi,

int array2[1..9]=[13, 18, 13, 14, 13, 16, 14, 21, 13];

int arrayQ[i in 1..9]=count(array2,array2[i]);

int maxOccur=max(i in 1..9) arrayQ[i];

int maxValue=first({array2[i] | i in 1..9 :arrayQ[i]==maxOccur});

execute
{
 writeln(maxValue);
}

will do the job

regards

Alex Fleischer

Originally posted by: Calvin Sun Hainan

Thanks. Realy smart solution. I never thought about using count in this way. The following is my solution, and it is not efficient.

tuple twoInt {

  int a;

  int b;

}

twoInt array[1..9] = [<13,1>, <18,1>, <13,1>, <14,1>, <13,1>, <16,1>, <14,1>, <21,1>, <13,1>];

{int} diffValuesInArray = {x.a | x in array};

int countForEachValue[diffValuesInArray] = [d : sum (x in array : x.a == d) x.b  | d in diffValuesInArray];

int mode;

execute {

  var count = 0;

  for (var x in diffValuesInArray) {

    if ( count < countForEachValue[x]) {

      mode = x;

      count = countForEachValue[x];

  }

}

Originally posted by: Calvin Sun Hainan

I realize that "count" only works with int arrays. If my array is float, I think count will not work. I may still need to switch to using OPL script.

count

int

count(int[ ],int)
count(dvar int[ ],int) )