Method: NMatrix#lower_triangle!

Defined in:
lib/nmatrix/nmatrix.rb

#lower_triangle!(k = 0) ⇒ Object Also known as: tril!

call-seq:

lower_triangle! -> NMatrix
lower_triangle!(k) -> NMatrix
tril! -> NMatrix
tril!(k) -> NMatrix

Deletes the upper triangular portion of the matrix (in-place) so only the lower portion remains.

  • Arguments :

    • k -> Integer. How many extra diagonals to include in the deletion.

Raises:

  • (NotImplementedError) 


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# File 'lib/nmatrix/nmatrix.rb', line 829

def lower_triangle!(k = 0)
  raise(NotImplementedError, "only implemented for 2D matrices") if self.shape.size > 2

  (0...self.shape[0]).each do |i|
    if i + k < shape[0]
      self[i, (i+k+1)...self.shape[1]] = 0
    end
  end
  self
end