How to constrain the solution as an integer in Solve Block?

Forum|Forum|10 years ago
September 30, 2015
4 replies
3172 views

Hi, everyone,

Is there a way to have an integer constraint in solve block?

Say, the solution is in form of sin(t) or cos(t), I want to check the maximum values after several periods.

Please see attachment.

Thank you very much.

Shawn

1_Integer-Constraint-mcdx.zip

Other

R

RichardJ

19-Tanzanite

Is there a way to have an integer constraint in solve block?

No. This used to be possible in MC11 using an extension pack, but it was not compatible with MC12, and was never ported.

A

AndyWesterman

12-Amethyst

Unfortunately I only have Prime 2, so I can't read your sheet.

There are a few symbols in the ribbon menu that may help :

gives a test for T {is a member of} (set of all integers}

adding to a simple solve block will force it to fail if the answer is not an integer.

Whether it is possible for the solve block to always find alternate solutions I don't know, but the attached shows an instance where it can.

Hope this is helpful

Regards

Andy

1_Z-mcdx.zip

R

RichardJ

19-Tanzanite

I admit I'm not sure how the Knitro solvers in Prime handle integer constraints, but most solvers don't like them. Most solvers head downhill on the error surface, and if the error surface is not smooth they can't handle it. Asking for integer solutions makes it very non-smooth, with many local minima that are singularities at the integer solution points.

W

Werner_E

25-Diamond I

Unfortunately my P3.0 can't read your 3.1 file, either, as PTC has decided, that even every subversion should get its own incompatible file format and no one should be able to read newer formats nor be able to save in older file formats.

Sometime (while not often) the symbolic "assume, t=integer" helps as here with Andy's example