Strange (lack of) round-off error using norm

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Mariano
Mariano on 16 Feb 2019
Answered: Mariano on 17 Feb 2019
Hello,
I have found this behaviour:
>> format hex
>> p=[sqrt(2) sqrt(2)]*1e3;
>> sqrt(sum(p.^2))
ans =
409f400000000001
>> norm(p)
ans =
409f400000000000
I understand the round-off error using sqrt. What I do not understand is how does norm do to avoid it.
Thanks,
Mariano
  2 Comments
Walter Roberson
Walter Roberson on 17 Feb 2019
R2018b on my Mac, I do see the different values.

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Answers (1)

Mariano
Mariano on 17 Feb 2019
I should have said version and computer:
R2018b on Windows 64bits.

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