Stack Overflow
Stack Overflow

Questions tagged [gap-system]

GAP (Groups, Algorithms and Programming) is an open source mathematical software system for discrete computational algebra (https://www.gap-system.org). Ask here non-mathematical questions about programming in GAP; for mathematical questions use the (gap) tag at Mathematics Q&A site: https://math.stackexchange.com/questions/tagged/gap. Other places to ask about GAP are the GAP Forum and GAP Support: https://www.gap-system.org/Contacts/Forum/forum.html

This is the tag for questions related to the computational algebra system GAP.

GAP (Groups, Algorithms and Programming) is a system for computational discrete algebra, with particular emphasis on Computational Group Theory. It provides a programming language, a library of thousands of functions implementing algebraic algorithms written in the GAP language as well as large data libraries of algebraic objects. GAP is used in research and teaching for studying groups and their representations, rings, vector spaces, algebras, combinatorial structures, and more.

If you want to ask a question in this category, please note that there are well-established support channels for GAP users such as GAP Forum and GAP Support which may be more suitable places for such questions with a different (though possibly intersecting) audience, and with a different response rate (which may be faster or slower, dependently on your question). While there may be GAP users and some authors of GAP and/or its packages among the users of this Q&A site, please do not assume that the question on GAP asked here will necessarily be noticed by them.

It may also happen that your question is already answered in the Frequently Asked Questions section of the GAP website or in the GAP Forum (to search GAP Forum archives, click here), or under the "gap" tag on the Mathematics Q&A website.

Finally, if you think that you have discovered a bug in the GAP system, the recommended way to report it is to use the GAP issue tracker on GitHub. Many packages have their own issue trackers, which you can find following the links here.

56 questions
1
vote
0 answers

Create Generation matrix from Function to check CCZ

Here is an example of checking CCZ-equivalence. How to rewrite the following function CF from Magma to GAP-system? p=2;n=6; function CF(f) M:=Matrix( 2*n+1, p^n, [1: x in GF] cat [Trace(a^i * x): x in GF, i in…
Konstantin
  • 11
  • 1
1
vote
1 answer

Install GAP Packages in SAGE 8.9

I'm running SageMath 8.9 on Windows 10. I'd like to run the following code: gap.eval('LoadPackage("grape")') gap.eval("n := 5") gap.eval("grp := Group([ (1,2,3,4,5), (1,2,4,3) ])") gap.eval("Der := []; for x in grp do if NrMovedPoints(x)=n then…
Dan P.
  • 269
  • 2
  • 9
1
vote
1 answer

How to upload and import gap packages on CoCalc

I am trying to use the gap package SimpComp on CoCalc in Sage. However, the way in which packages are supposed to be installed and imported is completely unclear to me. There are multiple locations in the directories that have to do with gap, I have…
BetaBetaAlpha
  • 11
  • 2
1
vote
0 answers

How to get GAP to recognize Read("filename.g") when called using a python sub-process

I'm doing research in computational number theory and I use a software package called GAP (Groups, Algebra and Programming). I want to set up a system in which I can call a python script to perform all of the set-up for me so that I can run multiple…
Qhef
  • 11
  • 3
1
vote
0 answers

Defining a particular polynomial ring in some CAS (Computer Algebra System)

I'm interested in defining the following polynomial quotient ring in some CAS (Singular, GAP, Sage, etc.): R = GF(256)[x] / (x^4 + 1) Specifically, R is the set of all polynomials of degree at most 3, whose coefficients belong to GF(256). Two…
Sadeq Dousti
  • 3,346
  • 6
  • 35
  • 53
1
vote
1 answer

GAP Root Paths: Cannot find any files

I am trying to install GAP on my PC, but am not having much luck with the root directory. On my work computer, I can put a file "test.g" in C:\gap4r8\, call Read("test.g") and it will load. However, this does not work on my home PC; I get: Error,…
Mark Butler
  • 895
  • 1
  • 5
  • 18
1
vote
1 answer

Does GAP always complete its task before returning the prompt?

In investigating a certain problem, I let a GAP program run for a few days. It eventually terminated and presented me the prompt again. Does this guarantee that it ran the previously entered code or could something else have happened? If something…
Tanner Carawan
  • 11
  • 1
1
vote
1 answer

GAP programming: variable assignment and functions

This question is about the GAP and the GAP programming language: I would like to write code that will compute the following formula: (n^+1)/GcdInt(n^2+1, 2^(Tau(n^2+1))); for the first 100,000 integers n. Here is what I have so…
user3195446
  • 147
  • 1
  • 13
1
vote
0 answers

Dancing Links in GAP

I am working on a combinatorics problem that has connections to group theory, and I decided to do the group theoretic part in GAP (b/c GAP is really efficient in that area). Now, the computations involve finding an exact cover in a certain…
jpvee
  • 913
  • 1
  • 15
  • 23
1
vote
1 answer

How can you make an interface GAP for Haskell?

I need to use GAP with Haskell. How can you make an interface for Haskell to call GAP's functions?
Khovanov
  • 33
  • 7
1
vote
1 answer

how to redirect GAP output to a text file on a local drive?

Example m1; [ [ -1, 0, 0, 0, 0, 0 ], [ 1, 1, -1, 0, 0, 0 ], [ 0, 0, -1, 0, 0, 0 ], [ 0, 0, 0, -1, 0, 0 ], [ 0, 0, 0, 1, 1, 0 ], [ 0, 0, 0, 0, 0, -1 ] ] in the Windows version of the GAP system, how do it redirect any output to a text file on a…
ControlPoly
  • 717
  • 2
  • 10
  • 21
0
votes
0 answers

Defining a representation on $SL_2(\mathbb{Z})$

I want to define a representation on $\text{SL}_2(\mathbb{Z})$, or generally, over any free group with two generators on GAP. I am using repsn package for this. I have written the code LoadPackage("repsn");; f := FreeGroup("x","y");; G := f /…
dragoboy
  • 101
0
votes
0 answers

GAP-system: Generate a list of duplicate elements

Maybe this question sounds stupid, but is there a function which e.g. takes the inputs a and 5 and outputs a list [a,a,a,a,a] in GAP-system, similar to numpy.full() in python? I have searched extensively in the GAP manual, but to no avail. I could…
Ooooscar
  • 1
  • 1
0
votes
0 answers

Characters of SL_2(\mathbb{Z}/4\mathbb{Z})

I need to have description of all the characters of group $\mathrm{SL}_2(\mathbb{Z}/8\mathbb{Z})$. I am implementing the following code on Sage online (changing the language to GAP). \gap> g := SL(2, Integers mod 8); gap> c :=…
dragoboy
  • 101
0
votes
1 answer

Seeking the minimal generating set of a AffineCrystGroup

Based on the data provided on page 21 of the book Computer Algebra and Materials Physics, I tried to do the following testing in GAP: gap> M1Right:=[[0,0,1,0],[1,0,0,0],[0,-1,0,0],[1/4,1/4,1/4,1]];; gap>…
Hongyi Zhao
  • 77
  • 1
  • 6
1 2
3
4