如何计算列表中的最高、最低和平均数？

Question

cpuSensorValues.Add(sensor.Value);
if (cpuSensorValues.Count == 300)
{
    for (int i = 0; i < cpuSensorValues.Count; i++)
    {    
        Logger.Write("The Current CPU Temperature Is ===> " + sensor.Value);
    }
    cpuSensorValues = new List<float?>();
}

I'm adding to the List<float?> cpuSensorValues every second a value. Then when it's getting to 300 values I want to calculate the highest number the lowest number and the average number from the List write each number to the logger and then to make a new instance to the List.

The problem is how can I calculate these 3 numbers?

Answer 1

You could use Enumerable.Max() , Enumerable.Min() , and Enumerable.Average() :

var min = cpuSensorValues.Min();
var max = cpuSensorValues.Max();
var avg = cpuSensorValues.Average();

However, this will enumerate the list 3 times (once per call). In practice, that's likely not going to be a problem, but if it is, you could just handle this yourself:

// Returns min/max/average, ignoring null elements
Tuple<float,float,float> ComputeStats(IEnumerable<float?> values)
{
     float min = float.MaxValue;
     float max = float.MinValue;
     float total = 0.0;
     int count = 0;

     foreach(var value in values)
     {
        if (value.HasValue)
        {
            min = Math.Min(min, value.Value);
            max = Math.Max(max, value.Value);
            total += value.Value;
            ++count;
        }
     }

     return Tuple.Create(min, max, total / count);
}

Given that you're adding the values to the list yourself - you could even keep a running total + min and max as you go. This would completely avoid needing to enumerate (or even store) the values. The code above could easily be modified to handle this without storing the values in a List<T> at all.