# File lib/matrix.rb, line 1130
  def +(v)
    case v
    when Vector
      Vector.Raise ErrDimensionMismatch if size != v.size
      els = collect2(v) {
        |v1, v2|
        v1 + v2
      }
      Vector.elements(els, false)
    when Matrix
      Matrix.column_vector(self) + v
    else
      s, x = v.coerce(self)
      s + x
    end
  end