ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Fri, 26 Sep 2014 16:19:43 +0200Computing Galois group of a polynomial?https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/ Here's my attempt so far:
x = polygen(QQ, 'x');
K.<z> = NumberField(x^4+x^2+2*x+1)
G = K.galois_group(type='gap')
And now I get several pages of error messages beginning with
verbose 0 (1780: permgroup_named.py, cardinality) Warning: TransitiveGroups requires the GAP database package. Please install it with ``sage -i database_gap``.
However! - I have installed this:
install_package()
[...
'database_gap-4.7.4',
...]
Anybody got any ideas on where I can go from here?Fri, 26 Sep 2014 08:41:20 +0200https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/Comment by tmonteil for <p>Here's my attempt so far:</p>
<pre><code>x = polygen(QQ, 'x');
K.<z> = NumberField(x^4+x^2+2*x+1)
G = K.galois_group(type='gap')
</code></pre>
<p>And now I get several pages of error messages beginning with</p>
<pre><code>verbose 0 (1780: permgroup_named.py, cardinality) Warning: TransitiveGroups requires the GAP database package. Please install it with ``sage -i database_gap``.
</code></pre>
<p>However! - I have installed this:</p>
<pre><code>install_package()
[...
'database_gap-4.7.4',
...]
</code></pre>
<p>Anybody got any ideas on where I can go from here?</p>
https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?comment=24292#post-id-24292It woks for me (with Sage 6.4.beta3 and database_gap-4.7.5), i got :
Galois group Transitive group number 3 of degree 4 of the Number Field in z with defining polynomial x^4 + x^2 + 2*x + 1
What is your configuration ?Fri, 26 Sep 2014 10:28:03 +0200https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?comment=24292#post-id-24292Answer by Dima for <p>Here's my attempt so far:</p>
<pre><code>x = polygen(QQ, 'x');
K.<z> = NumberField(x^4+x^2+2*x+1)
G = K.galois_group(type='gap')
</code></pre>
<p>And now I get several pages of error messages beginning with</p>
<pre><code>verbose 0 (1780: permgroup_named.py, cardinality) Warning: TransitiveGroups requires the GAP database package. Please install it with ``sage -i database_gap``.
</code></pre>
<p>However! - I have installed this:</p>
<pre><code>install_package()
[...
'database_gap-4.7.4',
...]
</code></pre>
<p>Anybody got any ideas on where I can go from here?</p>
https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?answer=24291#post-id-24291`install_package()` might be slightly broken at the moment, in the course of transition to git. Did you try running `sage -i database_gap`, as the error message says?
(your example works for me just fine).Fri, 26 Sep 2014 10:24:03 +0200https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?answer=24291#post-id-24291Comment by Alasdair for <p><code>install_package()</code> might be slightly broken at the moment, in the course of transition to git. Did you try running <code>sage -i database_gap</code>, as the error message says?</p>
<p>(your example works for me just fine).</p>
https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?comment=24298#post-id-24298Whenever I try to reinstall database_gap, either with `sage -i database_gap` or with 'install_package('databse_gap') from within Sage, I get an error that it's already installed. I tried also with `install_package('database_gap, force=True)` but that gave a different error: ValueError: There is no package name starting with 'database_gap'. I'll try again later in case there's a network issue.Fri, 26 Sep 2014 13:30:14 +0200https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?comment=24298#post-id-24298Comment by Dima for <p><code>install_package()</code> might be slightly broken at the moment, in the course of transition to git. Did you try running <code>sage -i database_gap</code>, as the error message says?</p>
<p>(your example works for me just fine).</p>
https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?comment=24301#post-id-24301`sage -f database_gap` will force a reinstall.Fri, 26 Sep 2014 14:19:55 +0200https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?comment=24301#post-id-24301Comment by Dima for <p><code>install_package()</code> might be slightly broken at the moment, in the course of transition to git. Did you try running <code>sage -i database_gap</code>, as the error message says?</p>
<p>(your example works for me just fine).</p>
https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?comment=24302#post-id-24302if this doesn't work, what is the output of `gap_console()` at your Sage prompt?Fri, 26 Sep 2014 14:28:19 +0200https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?comment=24302#post-id-24302Comment by Alasdair for <p><code>install_package()</code> might be slightly broken at the moment, in the course of transition to git. Did you try running <code>sage -i database_gap</code>, as the error message says?</p>
<p>(your example works for me just fine).</p>
https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?comment=24305#post-id-24305It's not that - I've adjusted the ownership and still it doesn't work. So I'm installing the package again...wait a bit... yes - now it works!Fri, 26 Sep 2014 16:19:43 +0200https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?comment=24305#post-id-24305Comment by Alasdair for <p><code>install_package()</code> might be slightly broken at the moment, in the course of transition to git. Did you try running <code>sage -i database_gap</code>, as the error message says?</p>
<p>(your example works for me just fine).</p>
https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?comment=24304#post-id-24304I reinstalled it (as root) using 'sage -f database_gap' as Dima suggests, and then it works fine if I run Sage as root. However, if I run Sage as an ordinary user, I still receive errors that the GAP database package is not installed. But trying to run 'sage -f database_gap' as an ordinary user gives me the error that I can't write to the /opt/sage-6.2 directory. However, gap_console() from both root and ordinary user gives the same output; that the Components are: trans 1.0, prim 2.1, small* 1.0, id* 1.0. Maybe there's some file ownership issue by which an ordinary user can't access the GAP packages installed by root?Fri, 26 Sep 2014 15:13:37 +0200https://ask.sagemath.org/question/24289/computing-galois-group-of-a-polynomial/?comment=24304#post-id-24304