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To check whether a variable is an integer?

Posted May 2, 2012, 12:38 p.m. EDT 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 May 6, 2012, 7:16 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago May 2, 2012, 5:25 p.m. EDT
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 May 2, 2012, 5:34 p.m. EDT
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 May 3, 2012, 3:05 a.m. EDT
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 May 3, 2012, 10:02 a.m. EDT
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 May 6, 2012, 7:16 a.m. EDT
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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