Method: Stick::Matrix#*

Defined in:
lib/stick/matrix/core.rb

#*(m) ⇒ Object

Matrix multiplication.

Matrix[[2,4], [6,8]] * Matrix.identity(2)
  => 2 4
     6 8



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# File 'lib/stick/matrix/core.rb', line 462

def *(m) # m is matrix or vector or number
  case(m)
  when Numeric
    rows = @rows.collect {
      |row|
      row.collect {
        |e|
        e * m
      }
    }
    return Matrix.rows(rows, false)
  when Vector
    m = Matrix.column_vector(m)
    r = self * m
    return r.column(0)
  when Matrix
    Matrix.Raise ErrDimensionMismatch if column_size != m.row_size

    rows = (0 .. row_size - 1).collect {
      |i|
      (0 .. m.column_size - 1).collect {
        |j|
        vij = 0
        0.upto(column_size - 1) do
          |k|
          vij += self[i, k] * m[k, j]
        end
        vij
      }
    }
    return Matrix.rows(rows, false)
  else
    x, y = m.coerce(self)
    return x * y
  end
end