mfirstNot#

swordfish.function.mfirstNot()#

If X is a vector:

  • If k is not specified, return the first element of X that is not null in a sliding window.

  • If k is specified, return the first element of X that is neither k nor null in the window.

If X is a matrix or table, conduct the aforementioned calculation within each column of X. The result is a vector.

Parameters:
  • X (Constant) – A vector/matrix/table/tuple (with scalars or equal-length vectors)/dictionary.

  • window (Constant) – An integer no smaller than 2 or a scalar of DURATION type indicating the size of the sliding window. Note: The window size is capped at 102400 when m-functions are used in the streaming engines.

  • k (Constant, optional) – A numeric or string scalar indicating the value to be matched.

  • minPeriods (Constant, optional) – A positive integer indicating the minimum number of observations in a window required to be not null (otherwise the result is NULL).