Definitive answer on the correct str2double behavior for the string '10 20'

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Under Windows 7 with R2014a, str2double('10 20') evaluates to NaN. I believe this is the correct behavior, per the documentation.
A colleague working in a Linux environment with R2014a reports that str2double('10 20') evaluates to an array [10 20].
1. Is this possible (without overloading)? 2. Am I correct that the intended evaluation (without overloading) is NaN?
Thanks so much.

Accepted Answer

per isakson
per isakson on 10 Jul 2014
Edited: per isakson on 10 Jul 2014
"str2double('10 20') evaluates to an array [10 20]." . If that is the case it should be reported as a bug
  1. It should not be possible without overloading
  2. You are correct
I advise against unrestricted use of str2num. It uses eval and ... , e.g.
>> str2num( 'sin([0:0.8:2*pi])')
ans =
0 0.7174 0.9996 0.6755 -0.0584 -0.7568 -0.9962 -0.6313
IMO: sscanf is a better alternative
>> vec = sscanf( '10 20', '%f' )
vec =
10
20

More Answers (1)

Azzi Abdelmalek
Azzi Abdelmalek on 9 Jul 2014
Edited: Azzi Abdelmalek on 9 Jul 2014
str2num('10 20')
will give an array, maybe that's what your colleague has used
  1 Comment
Nicholas
Nicholas on 10 Jul 2014
Thanks Azzi. Yes, we ended up changing the code to use str2num, to give OS independent results. But I am still curious about: a) the definitive (Mathworks intended) behavior of str2double; and b) whether OS can in fact affect behavior (I don't have a Linux machine here to investigate further).

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