method

**

v1_8_7_330 - Show latest stable - 0 notes - Class: Matrix

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What's this?

**(other) public

Matrix exponentiation. Defined for integer powers only. Equivalent to multiplying the matrix by itself N times.

Matrix[[7,6], [3,9]] ** 2
  => 67 96
     48 99

Show source

# File lib/matrix.rb, line 644
  def ** (other)
    if other.kind_of?(Integer)
      x = self
      if other <= 0
        x = self.inverse
        return Matrix.identity(self.column_size) if other == 0
        other = -other
      end
      z = x
      n = other  - 1
      while n != 0
        while (div, mod = n.divmod(2)
               mod == 0)
          x = x * x
          n = div
        end
        z *= x
        n -= 1
      end
      z
    elsif other.kind_of?(Float) || defined?(Rational) && other.kind_of?(Rational)
      Matrix.Raise ErrOperationNotDefined, "**"
    else
      Matrix.Raise ErrOperationNotDefined, "**"
    end
  end

**

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