## Problems with tropical polytopes with rational vertices

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Srlam
Posts: 3
Joined: 14 Feb 2019, 10:37

### Problems with tropical polytopes with rational vertices

Hello, I'm trying to input a tropical polytope whose vertices have coordinates in Q and not in Z.
This is the input

Code: Select all

$p=new Polytope <Min> (POINTS=>[[0,0,0,0],[0,1,2,3],[0,4,1,7], [0, 4/9, 1/9, 7/9], [0, 1/2, 1/8, 7/8],[0, 4/7, 1/7, 1], [0, 2/3, 1/6, 7/6],[0, 4/5, 1/5, 7/5], [0, 1, 1/4, 7/4],[0, 4/3, 1/3, 7/3], [0, 2, 1/2, 7/2], [0, 4, 1, 7]]) ; I get the following error: Code: Select all polymake: ERROR: Shared module compilation failed; most likely due to a type mismatch. Set the variable$Polymake::User::Verbose::cpp to a positive value and repeat for more details.
Can you help me with this?
Thanks

joswig
Main Author
Posts: 216
Joined: 24 Dec 2010, 11:10

### Re: Problems with tropical polytopes with rational vertices

Which version of polymake are you using? We just released version 3.3, and there it works.

It is possible that in some older versions the types get messed up. Beware that the property POINTS takes a small object of type Matrix<TropicalNumber<Min>>. Object of type Rational should automatically convert to TropicalNumber<Min> but not conversely. Maybe you can solve your problem (even in an old version of polymake) by explicitly creating the matrix object first and then use it to construct the tropical polytope.

Srlam
Posts: 3
Joined: 14 Feb 2019, 10:37

### Re: Problems with tropical polytopes with rational vertices

Thanks!
I tried to create a matrix with rational entries first but it still gives me problems:

Code: Select all

$m = new Matrix<TropicalNumber<Min>>([[0,1/2,4]]); polymake: ERROR: Shared module compilation failed; most likely due to a type mismatch. Set the variable$Polymake::User::Verbose::cpp to a positive value and repeat for more details.
I have version 3.2 of polymake and I'm running a Mac so I guess I need to wait a bit for the release of 3.3 for Mac.

gawrilow
Main Author
Posts: 349
Joined: 25 Dec 2010, 17:40

### Re: Problems with tropical polytopes with rational vertices

There is nothing wrong with your input. Must be some strange installation problem.
Are you using polymake built from the source code or from a disk image?

Srlam
Posts: 3
Joined: 14 Feb 2019, 10:37

### Re: Problems with tropical polytopes with rational vertices

I've installed polymake using the disc image.

gawrilow
Main Author
Posts: 349
Joined: 25 Dec 2010, 17:40

### Re: Problems with tropical polytopes with rational vertices

While waiting for the new disk image, you can try out the docker image of the new release.