private static int GetNumDiskAccess(int rtreeSize, int strategy, int minEntry, int maxEntry)
{
var featurePath = StrategyMap[strategy].Item1;
var featureDim = StrategyMap[strategy].Item2;
var nums = Enumerable.Range(0, NumImages).ToList();
nums.Shuffle();
var tree = new RTree <string>(maxEntry, minEntry);
var featureLines = File.ReadAllLines(featurePath);
var points = featureLines.Select(s =>
{
var slices = s.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
return(new Point(featureDim, slices.Select(double.Parse).ToList()));
}).ToList();
var imageNames = File.ReadAllLines(ImageFilePath);
for (var i = 0; i < rtreeSize; i++)
{
tree.AddRecord(new Rectangle(featureDim, points[nums[i]], points[nums[i]]), imageNames[nums[i]]);
}
var mbr = tree.GetRootMbr();
var ratio = Math.Pow(1d / 2, 1d / featureDim);
const int queryTimes = 1024;
var countSum = 0;
for (var i = 0; i < queryTimes; i++)
{
var queryMinBound = Enumerable.Repeat(0d, featureDim).ToList();
var queryMaxBound = Enumerable.Repeat(0d, featureDim).ToList();
for (var dim = 0; dim < featureDim; dim++)
{
var length = mbr.MaxBoundries[dim] - mbr.MinBoundries[dim];
var sideLength = length * ratio;
var start = mbr.MinBoundries[dim] + new Random(DateTime.Now.Millisecond).NextDouble() *
(mbr.MaxBoundries[dim] - sideLength - mbr.MinBoundries[dim]);
var end = start + sideLength;
queryMinBound[dim] = start;
queryMaxBound[dim] = end;
}
var queryRect = new Rectangle(featureDim, queryMinBound, queryMaxBound);
tree.GetContainedItems(queryRect, out var count);
countSum += count;
}
return(countSum / queryTimes);
}