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To check whether a variable is an integer?

Posted 2 mai 2012, 12:38 UTC−4 Materials, Studies & Solvers, Structural Mechanics Version 4.2 5 Replies

Lakshmi Selvakumaran
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Hi,

Is it possible to check whether the value of the variable at a particular timestep is an integer? Is there any function that I can use to find this?

Thanks.
5 Replies Last Post 6 mai 2012, 07:16 UTC−4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 2 mai 2012, 17:25 UTC−4
Hi

never hear of that, but perhaps something like ((x-floor(x))<eps) might work, but check carefully the positive and negative side effects, and you ight need several times of "eps" if x is getting large

--
Good luck
Ivar
Hi never hear of that, but perhaps something like ((x-floor(x))
Mranal Jain
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Posted: 1 decade ago 2 mai 2012, 17:34 UTC−4
Possibly, we could use the 'mod' function i.e.

If mod(var,1) == 0 , it is an integer;

If you use matlab scripting 'isinteger' function could be used.
Possibly, we could use the 'mod' function i.e. If mod(var,1) == 0 , it is an integer; If you use matlab scripting 'isinteger' function could be used.
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 3 mai 2012, 03:05 UTC−4
Hi

but what about the numerical precision ? in "automatic" mode COMSOL might stop and solve for a value very close to the integer, but not exactly "on" it

--
Good luck
Ivar
Hi but what about the numerical precision ? in "automatic" mode COMSOL might stop and solve for a value very close to the integer, but not exactly "on" it -- Good luck Ivar
Mranal Jain
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Posted: 1 decade ago 3 mai 2012, 10:02 UTC−4
Yes, we need to use some threshold (eps) as Ivar suggested in last post.
Yes, we need to use some threshold (eps) as Ivar suggested in last post.
Lakshmi Selvakumaran
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Posted: 1 decade ago 6 mai 2012, 07:16 UTC−4
Thanks Ivar and Mranal. I used (ceil(t)-t<eps) and it works well. Thanks for your input.
Thanks Ivar and Mranal. I used (ceil(t)-t

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