C#

var q = 
                    from a1 in dt_Jobs.AsEnumerable()
                    orderby a1.Field<String>("City")
                    where (a1.Field<String>("City") != null)
                    select a1.Field<String>("City");
                var lstCity = q.Distinct().ToList();
                cboCity.DataSource = lstCity;

public static IEnumerable<Tuple<int, double>> LocalPeakMinMax(IEnumerable<double> source, int windowSize)
{
    if (windowSize < 2) windowSize = 2;
    
    windowSize = windowSize - windowSize % 2 + 1;
    int halfWindow = windowSize / 2;
    int index = 0;
    var before = new Queue<double>(Enumerable.Repeat(double.NegativeInfinity, halfWindow));
    var after = new Queue<double>(source.Take(halfWindow + 1));

    foreach (double d in source.Skip(halfWindow + 1).Concat(Enumerable.Repeat(double.NegativeInfinity, halfWindow + 1)))
    {
        double curVal = after.Dequeue();
        if (before.All(x => curVal > x ) && after.All(x => curVal >= x ))
        {
            yield return Tuple.Create(index, curVal);
        }
        else 
        if (before.All(x => curVal <= x) && after.All(x => curVal < x))
        {
            yield return Tuple.Create(index, curVal);
        }

        before.Dequeue();
        before.Enqueue(curVal);
        after.Enqueue(d);
        index++;
        }
    }

double[] trace =
{
  47.92370605, 44, 49, 46.31715393, 44.98129654, 46.17653275, 78, 73, 82, 63, 69, 41.72979736, 41.13000488,
  41.49586487, 37, 40, 30, 40.79894257, 40.65593719, 41.37298584, 39.13498688, 55, 51, 60, 39.3440094,
  38.51491547, 42, 35.12589264
};
for (int i = 1; i < trace.Length - 1; i++)
{
  double deltaLeft = trace[i - 1];
  double deltaRight = trace[i + 1];

  if (trace[i] - deltaLeft >= 6 && trace[i] - deltaRight >= 6)
  {
    Console.WriteLine($"Peak at {i + 1}");
  }
}

Member 12616185 wrote:

The following data represents a typical trace. Only points 9,11, and 24 are real points that should be returnd.

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]

Nigel_Davison wrote:

LINQ isn't everything, and by elegant I meant not done with a 100 for/if loops etc.

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]