発見。
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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
