foreachActive functionality

[kundan kumar]

Can someone help me to understand the usage of "foreachActive"  function
introduced for the Vectors.

I am trying to understand its usage in MultivariateOnlineSummarizer class
for summary statistics.


sample.foreachActive { (index, value) =>
      if (value != 0.0) {
        if (currMax(index) < value) {
          currMax(index) = value
        }
        if (currMin(index) > value) {
          currMin(index) = value
        }

        val prevMean = currMean(index)
        val diff = value - prevMean
        currMean(index) = prevMean + diff / (nnz(index) + 1.0)
        currM2n(index) += (value - currMean(index)) * diff
        currM2(index) += value * value
        currL1(index) += math.abs(value)

        nnz(index) += 1.0
      }
    }

Regards,
Kundan