ASKSAGE: Sage Q&A Forum - Individual question feedhttp://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Wed, 07 Jan 2015 01:52:17 -0600Error plotting root systems in Sagehttp://ask.sagemath.org/question/25415/error-plotting-root-systems-in-sage/ I am trying to use the Sage package for root systems, but it keeps returning an error. Here is what I am trying to do in the Notebook of Sage 5.7: I enter exactly the following lines from the tutorial for visualizing root systems
sage: L = RootSystem(["A",2]).ambient_space()
sage: L.plot()
The output I get is a traceback ending in 'unsupported operand parent(s) for '*': Full matrix Space of 2 by 2 dense matrices over real field with 53 bits of precision and vector space of dimension 3 over rational field'
I do not understand what I am doing wrong and what this message means. I am a newcomer to sage and all I want is to print a root system with some weights added for illustration purposes. I would appreciate any pointers.Tue, 06 Jan 2015 15:45:41 -0600http://ask.sagemath.org/question/25415/error-plotting-root-systems-in-sage/Answer by kcrisman for <p>I am trying to use the Sage package for root systems, but it keeps returning an error. Here is what I am trying to do in the Notebook of Sage 5.7: I enter exactly the following lines from the tutorial for visualizing root systems</p>
<p>sage: L = RootSystem(["A",2]).ambient_space()</p>
<p>sage: L.plot()</p>
<p>The output I get is a traceback ending in 'unsupported operand parent(s) for '*': Full matrix Space of 2 by 2 dense matrices over real field with 53 bits of precision and vector space of dimension 3 over rational field'</p>
<p>I do not understand what I am doing wrong and what this message means. I am a newcomer to sage and all I want is to print a root system with some weights added for illustration purposes. I would appreciate any pointers.</p>
http://ask.sagemath.org/question/25415/error-plotting-root-systems-in-sage/?answer=25416#post-id-25416This command works fine in Sage 6.2; see below. I can confirm that this does not work in Sage 5.2, apparently due to multiplying a matrix and a vector of incompatible sizes. Anyway, you are probably looking at the latest documentation but using an older version of Sage which didn't support that; luckily, upgrading is usually not too hard.
![Picture](http://sage.math.washington.edu/home/kcrisman/pic.png)Tue, 06 Jan 2015 20:52:22 -0600http://ask.sagemath.org/question/25415/error-plotting-root-systems-in-sage/?answer=25416#post-id-25416Comment by guest for <p>This command works fine in Sage 6.2; see below. I can confirm that this does not work in Sage 5.2, apparently due to multiplying a matrix and a vector of incompatible sizes. Anyway, you are probably looking at the latest documentation but using an older version of Sage which didn't support that; luckily, upgrading is usually not too hard.</p>
<p><img alt="Picture" src="http://sage.math.washington.edu/home/kcrisman/pic.png"/></p>
http://ask.sagemath.org/question/25415/error-plotting-root-systems-in-sage/?comment=25418#post-id-25418I accepted your answer; I am not sure why it does not appear as accepted. I am having some trouble navigating this site, for instance I clicked this comment box a minute ago and my browser crashed :(Wed, 07 Jan 2015 01:52:17 -0600http://ask.sagemath.org/question/25415/error-plotting-root-systems-in-sage/?comment=25418#post-id-25418Comment by guest for <p>This command works fine in Sage 6.2; see below. I can confirm that this does not work in Sage 5.2, apparently due to multiplying a matrix and a vector of incompatible sizes. Anyway, you are probably looking at the latest documentation but using an older version of Sage which didn't support that; luckily, upgrading is usually not too hard.</p>
<p><img alt="Picture" src="http://sage.math.washington.edu/home/kcrisman/pic.png"/></p>
http://ask.sagemath.org/question/25415/error-plotting-root-systems-in-sage/?comment=25417#post-id-25417Thank you; I will try updating.Tue, 06 Jan 2015 22:58:50 -0600http://ask.sagemath.org/question/25415/error-plotting-root-systems-in-sage/?comment=25417#post-id-25417