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JavaScript

function mostFrequentValueOf( arr ) {
    var counts = {};
    for( var i=0; i<arr.length; ++i ) {
        var val = arr[i];
        if( counts[val] )
            counts[val]++;
        else
            counts[val]=1;
    }
    var maxcnt=0, maxval;
    for( var val in counts ) {
        var cnt = counts[val];
        if( cnt > maxcnt ) {
            maxcnt = cnt;
            maxval = val;
        }
    }
    return maxval;
}

/*
02 02 25 27 32 47,
45 55 11 44 65 47,
12 02 56 48 65 25,
45 56 11 44 76 54,
*/

var columns = [ [02,45,12,45], [02,55,02,56], [25,11,56,11], [27,44,48,44], [32,65,65,76], [47,47,25,54] ];

alert( mostFrequentValueOf(columns[0]) );

var rows = [ [02, 02, 25, 27, 32, 47], [45, 55, 11, 44, 65, 47], [12, 02, 56, 48, 65, 25], [45, 56, 11, 44, 76, 54] ];

var column_idx=0, column=[];
for( var i=0; i<rows.length; ++i )
    column.push( rows[i][column_idx] );

alert( mostFrequentValueOf(column) );