func NewKMeans(X Matrix, metric MetricOp) *KMeans {
// initialize index to complete index iterating over all elements of X, unless defined otherwise
return &KMeans{
X: X,
Metric: metric,
Index: mlgo.Range(0, len(X)),
}
}
func NewDistances(X Matrix, metric MetricOp) (d *Distances) {
// each row of X is considered one data point
m := len(X)
// allocate space
D := make(Matrix, m)
for i := 0; i < m; i++ {
D[i] = make(Vector, m)
}
// calculate distances for lower and upper triangles together
for i := 0; i < m; i++ {
for j := i + 1; j < m; j++ {
d := metric(X[i], X[j])
D[i][j], D[j][i] = d, d
}
}
d = &Distances{rep: D, metric: metric, index: mlgo.Range(0, m)}
return
}