public void IndexPartitionMinimumCentroidTest()
{
// data is null
{
var target = IrisDataSet.GetClassPredictions();
var partition = IndexPartition.Create(target);
ArgumentExceptionAssert.Throw(
() =>
{
var actual = IndexPartition.MinimumCentroidLinkage(null, partition);
},
expectedType: typeof(ArgumentNullException),
expectedPartialMessage: ArgumentExceptionAssert.NullPartialMessage,
expectedParameterName: "data");
}
// partition is null
{
var data = IrisDataSet.GetAttributesAsDoubleMatrix();
ArgumentExceptionAssert.Throw(
() =>
{
var actual = IndexPartition.MinimumCentroidLinkage(data, null);
},
expectedType: typeof(ArgumentNullException),
expectedPartialMessage: ArgumentExceptionAssert.NullPartialMessage,
expectedParameterName: "partition");
}
// The first part contains an invalid index
{
var data = IrisDataSet.GetAttributesAsDoubleMatrix();
var target = IrisDataSet.GetClassPredictions();
var partition = IndexPartition.Create(target);
partition[1][0] = 100000;
ArgumentExceptionAssert.Throw(
() =>
{
var actual = IndexPartition.MinimumCentroidLinkage(data, partition);
},
expectedType: typeof(ArgumentException),
expectedPartialMessage: ImplementationServices.GetResourceString(
"STR_EXCEPT_INP_PART_CONTAINS_INVALID_INDEX"),
expectedParameterName: "partition");
}
// The second part contains an invalid index
{
var data = IrisDataSet.GetAttributesAsDoubleMatrix();
var target = IrisDataSet.GetClassPredictions();
var partition = IndexPartition.Create(target);
partition[2][0] = 100000;
ArgumentExceptionAssert.Throw(
() =>
{
var actual = IndexPartition.MinimumCentroidLinkage(data, partition);
},
expectedType: typeof(ArgumentException),
expectedPartialMessage: ImplementationServices.GetResourceString(
"STR_EXCEPT_INP_PART_CONTAINS_INVALID_INDEX"),
expectedParameterName: "partition");
}
// Valid input
{
var data = IrisDataSet.GetAttributesAsDoubleMatrix();
var target = IrisDataSet.GetClassPredictions();
var partition = IndexPartition.Create(target);
var actual = IndexPartition.MinimumCentroidLinkage(
data, partition);
List <double> linkages = new();
foreach (var leftId in partition.Identifiers)
{
var leftPart = partition[leftId];
var left = data[leftPart, ":"];
foreach (var rightId in partition.Identifiers)
{
if (rightId != leftId)
{
var rightPart = partition[rightId];
var right = data[rightPart, ":"];
linkages.Add(Distance.CentroidLinkage(left, right));
}
}
}
double expected = linkages.Min();
Assert.AreEqual(expected, actual, 1e-4);
}
}
