Tropical and ERROR: Can't use string ...while "strict refs" in use

[spmath]

I am fairly new to polymake. I was reading Section 6 of the article "Tropical Convex Hull Computations". They suggest the following code, but it does not run. Any help will be appreciated it. If it helps, I am running polymake version 2.13 in Ubuntu.
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~$ polymake -A tropical
tropical > $p = new TropicalPolytope<Rational>(POINTS => [[0,3,6],[0,5,2],[0,0,1],[1,5,0]]);
tropical > print @{rows_labeled($p->PSEUDOVERTICES)};
polymake: used package cddlib
Implementation of the double description method of Motzkin et al.
Copyright by Komei Fukuda.
http://www.ifor.math.ethz.ch/~fukuda/cdd_home/cdd.html

polymake: ERROR: Can't use string ("10") as an ARRAY ref while "strict refs" in use.

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What is the meaning of this message? How can I fix it?

Thanks!

[blorenz]

Hello,

please consider upgrading your polymake version.
The line in question was written for a very old polymake version 2.9.4 and with version 2.13 should work as follows:

Code: Select all

print rows_labeled($p->PSEUDOVERTICES);

A more up to date reference for similar computations is our tutorial on application tropical. Note that the code on that page requires polymake version 3.0.

Best,
Benjamin

[spmath]

Dear Benjamin,

Thank you! The code runs. I once tried to update my polymake, but after two hours in forums, instructions, commands, etc.. I could not do it. Of course, every computer is different and little problems may appear in each one. Now, I am running the code in cloud.sagemath.com. I will write them for upgrading their polymake version.

Best