func (m Matrix) TotalSamples() int {
	numSamples := 0
	for _, series := range m {
		numSamples += len(series.Points)
	}
	return numSamples
}
func (m Matrix) TotalSamples() int {
	numSamples := 0
	for _, series := range m {
		numSamples += len(series.Points)
	}
	return numSamples
}
// TotalSamples returns the total number of samples in the series within a matrix.