and on other graphs either? (e.g. on graphs.CycleGraph(7)) Start sage prompt (sage -sh) and check that you have the program called theta available: $ sage -sh
Starting subshell with Sage environment variables set. Don't forget to exit when you are done. Beware: * Do not do anything with other copies of Sage on your system. * Do not use this for installing Sage packages using "sage -i" or for running "make" at Sage's root directory. These should be done outside the Sage shell. Bypassing shell configuration files... Note: SAGE_ROOT=/home/dima/software/sage (sage-sh) dima@dimpase:~$ theta Usage: theta <graph> (sage-sh) dima@dimpase:~$ ------------- if you don't have it then reinstall csdp: sage -f csdp On Tuesday, May 10, 2016 at 5:14:09 PM UTC+1, Sihuang Hu wrote: > > It didn't work for me. :( > > sage: g=Graph([[0,1],[2,3]]) > sage: g.lovasz_theta() > --------------------------------------------------------------------------- > ValueError Traceback (most recent call last) > <ipython-input-2-1d4d0397a94f> in <module>() > ----> 1 g.lovasz_theta() > > /home/shhu/Documents/SageMath/local/lib/python2.7/site-packages/sage/graphs/lovasz_theta.pyc > > in lovasz_theta(graph) > 78 tf.close() > 79 lines = subprocess.check_output([os.path.join(SAGE_LOCAL, > 'bin', 'theta'), tf_name]) > ---> 80 return float(lines.split()[-1]) > > ValueError: could not convert string to float: failed. > > > 在 2016年5月10日星期二 UTC+3下午6:33:50，Dima Pasechnik写道： >> >> all this works for me just fine: >> >> sage: g=Graph([[0,1],[2,3]]) >> sage: g.lovasz_theta() >> 2.0 >> sage: G = graphs.CycleGraph(7) >> sage: V = Set(G.vertices()) >> sage: L = [] >> sage: for s in V.subsets(): >> ....: L.append(G.subgraph(s)) >> ....: >> sage: L[68].lovasz_theta() >> 2.0 >> >> Can you try the following: >> sage: g=Graph([[0,1],[2,3]]) >> sage: g.lovasz_theta() >> >> >> >> On Tuesday, May 10, 2016 at 2:32:04 PM UTC+1, Sihuang Hu wrote: >>> >>> The adjacency matrix of the graph is >>> >>> [0 1 0 0] >>> [1 0 0 0] >>> [0 0 0 1] >>> [0 0 1 0] >>> >>> >>> 在 2016年5月10日星期二 UTC+3下午4:30:06，Dima Pasechnik写道： >>>> >>>> What is your L[68] ? >>>> This is probably something like a graph without edges... >>>> >>>> On Tuesday, May 10, 2016 at 1:53:17 PM UTC+1, Sihuang Hu wrote: >>>>> >>>>> Thanks for the comments. >>>>> I have installed package 'csdp' before. I got this error after I >>>>> installed it. >>>>> >>>>> 在 2016年5月10日星期二 UTC+3下午3:32:59，vdelecroix写道： >>>>>> >>>>>> The error you get is quite strange. On my computer with sage-7.1 I >>>>>> got >>>>>> >>>>>> sage: graphs.CycleGraph(7).lovasz_theta() >>>>>> Traceback (most recent call last): ur ... >>>>>> PackageNotFoundError: the package 'csdp' was not found. You can >>>>>> install >>>>>> it by running 'sage -i csdp' in a shell >>>>>> >>>>>> Which is very explicit about what to do... could you install the csdp >>>>>> package and try again? >>>>>> >>>>>> On 10/05/16 06:58, Sihuang Hu wrote: >>>>>> > Hi guys, >>>>>> > >>>>>> > When I try to compute the lovasz theta number of some graph, it >>>>>> says that >>>>>> > >>>>>> > *ValueError: could not convert string to float: failed.:*G = >>>>>> > graphs.CycleGraph(7) >>>>>> > V = Set(G.vertices()) >>>>>> > L = [] >>>>>> > for s in V.subsets(): >>>>>> > L.append(G.subgraph(s)) >>>>>> > >>>>>> > L[68].lovasz_theta() >>>>>> > >>>>>> --------------------------------------------------------------------------- >>>>>> >>>>>> > ValueError Traceback (most recent >>>>>> call last) >>>>>> > <ipython-input-53-0ad2fb49c2b1> in <module>() >>>>>> > ----> 1 L[Integer(68)].lovasz_theta() >>>>>> > >>>>>> > >>>>>> /home/shhu/Documents/SageMath/local/lib/python2.7/site-packages/sage/graphs/lovasz_theta.pyc >>>>>> >>>>>> >>>>>> > in lovasz_theta(graph) >>>>>> > 78 tf.close() >>>>>> > 79 lines = >>>>>> subprocess.check_output([os.path.join(SAGE_LOCAL, >>>>>> > 'bin', 'theta'), tf_name]) >>>>>> > ---> 80 return float(lines.split()[-1]) >>>>>> > >>>>>> > ValueError: could not convert string to float: failed. >>>>>> > >>>>>> > Thanks in advance! >>>>>> > >>>>>> >>>>> -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
