Ask Your Question

rickhg12hs's profile - activity

2020-12-02 14:44:11 +0100 received badge  Famous Question (source)
2020-12-02 14:44:11 +0100 received badge  Notable Question (source)
2018-08-05 23:30:52 +0100 received badge  Notable Question (source)
2018-05-03 00:17:01 +0100 received badge  Nice Answer (source)
2018-04-26 19:43:09 +0100 received badge  Popular Question (source)
2017-10-12 02:03:40 +0100 received badge  Popular Question (source)
2017-10-12 02:03:40 +0100 received badge  Notable Question (source)
2017-10-12 02:03:40 +0100 received badge  Famous Question (source)
2017-07-18 00:03:08 +0100 asked a question Upgrade to latest versions of all packages

[Version 7.6, installed from source]

Is there a way to verify that all the latest versions of installed packages are the most recent stable versions?

What method is recommended to upgrade all installed packages?

2016-05-06 23:54:58 +0100 received badge  Taxonomist
2016-04-30 22:43:06 +0100 received badge  Famous Question (source)
2016-04-03 11:19:46 +0100 received badge  Famous Question (source)
2015-12-23 00:00:13 +0100 received badge  Notable Question (source)
2015-12-16 19:07:15 +0100 received badge  Popular Question (source)
2015-03-20 21:51:58 +0100 received badge  Notable Question (source)
2014-08-24 06:19:47 +0100 commented answer Create/Modify SageMathCloud Project to be Private

So what do the "eye" and the "padlock" icons mean in the project listing?

2014-08-23 05:27:15 +0100 asked a question Create/Modify SageMathCloud Project to be Private

I recently created a SageMathCloud project and the icon in the project listing does not show that it is private. I didn't see an option to make it private when I created it.

How does one create a private project and/or modify an existing project to be private?

2014-06-29 21:35:22 +0100 received badge  Notable Question (source)
2014-06-29 21:35:22 +0100 received badge  Popular Question (source)
2014-06-29 21:35:22 +0100 received badge  Famous Question (source)
2014-06-29 03:15:44 +0100 marked best answer Generate Maximal subsets based on mutual/subset property

Sorry for the imprecise language - I'm not a mathematician.

Given a list/set/dict/etc., is there a function/method available that will generate subsets, with the possibility of non-null intersections, based on some user defined mutual/subset property?

E.g., given a list [0,1,2,3,4,5], generate the maximal lists such that the maximum difference within each list is 3. For the given list, the function would produce [[0,1,2,3],[1,2,3,4],[2,3,4,5]]. For the list [0,3,9,10,17,30,33], this function would produce [[0,3],[9,10],[17],[30,33]].

This is different than the usual filtering operation in that the defining property is about the returned lists/sets/etc., not just about the individual elements.

Function should work with members of ZZ, QQ, RR, RDF, CC, CDF, and others if possible.

2014-06-29 03:15:40 +0100 marked best answer Sage Notebook, R, & problem rendering LaTeX

Using Sage 5.9 notebook, the output of:

show(r.summary(range(10)))

... shows the LaTeX source, not the rendered LaTeX.

N.B.: My first try generated an error stating that R package 'Hmisc' was required. From:

sage -R
install_package('Hmisc')

... seemed to go fine. The notebook was restarted and:

r.installed_packages()

... showed 'Hmisc' was indeed installed.

Is there some other trick to render R LaTeX output in the notebook?

2014-06-29 03:13:09 +0100 marked best answer MathJax Font Sizes and Spacing/Positioning in Notebook

I'd like to control the Latex fontsize in the notebook. In the first cell, I placed:

%html
<style>.MathJax {font-size: 200%;}</style>

... and in later cells' view() outputs the individual characters/symbols increase in size but the positioning/spacing gets all spread out and ugly.

What's the right/easy way to increase the latex fontsize in Sage's notebook and still have it look good?

2014-06-29 03:13:04 +0100 marked best answer How to smart clean home .sage directory?

I've upgraded my OS (Fedora) and Sage several times, changed host names, etc., and now my ~/.sage directory takes up 161 MBytes and has over 11,000 files. I know there are several things I want to keep, like e.g., the notebook worksheets, but I'm sure there's lots of stuff that can be deleted (temporary files?).

Is there a ~/.sage cleaner or a way to know for sure which of these files can be safely deleted since they will never be used again?

2014-05-30 23:06:36 +0100 received badge  Popular Question (source)
2014-01-23 12:34:10 +0100 received badge  Popular Question (source)
2013-12-23 04:32:28 +0100 commented answer Which packages optimize performance parameters during build?

So it's really only `ntl` and `atlas` that doing any build parameter performance testing?

2013-12-17 21:14:26 +0100 asked a question Which packages optimize performance parameters during build?

Which packages use performance testing during the build process to optimize it? For example, I know NTL and Atlas do some testing to pick the best parameters for the platform. What other packages do this?

If I want to rebuild the performance testing packages during system "low-load" times, how should that be done? Like this? [Edited to fix character case]

$ ./sage -f ntl  && ./sage -f atlas ... && ./sage -b

Are there dependencies? In what order should they be rebuilt?

2013-10-20 06:09:11 +0100 commented answer Accessing cloud via ssh

From experience, the git repos on Bitbucket work similarly.

2013-10-20 05:49:42 +0100 commented question what PI and e in p-adic number?
2013-10-20 05:42:25 +0100 answered a question hot to plot in cloud?

There are examples of various plots here: https://github.com/haraldschilly/sage...

2013-10-20 05:29:15 +0100 commented question why the ssl IS red use CHROME ?

Are you saying that you suspect a "man-in-the-middle" from your computer to https://cloud.sagemath.com/ ?

2013-10-20 05:00:31 +0100 commented answer Generate Maximal subsets based on mutual/subset property

Changed my mind about preferred solution after doing some performance testing. Determining maximal cliques seems to be *** orders of magnitude *** faster.

2013-10-20 04:58:26 +0100 commented answer Generate Maximal subsets based on mutual/subset property

After some preliminary testing, this algorithm is *** orders of magnitude *** faster than determining the maximal faces of the Simplical Complex.

2013-10-20 04:56:23 +0100 marked best answer Generate Maximal subsets based on mutual/subset property

You can also notice that your property defining the set B is a property that is tested on pairs of elements of A. Hence, you can construct the graph corresponding to admissible pairs:

sage: A = Set([0,3,9,10,17,30,33])
sage: G = Graph()
sage: G.add_vertices(A)
sage: for u,v in CartesianProduct(A,A):
....:    if u != v and max(u,v) - min(u,v) <=3:
....:        G.add_edge(u,v)

What you are looking for is the set of maximal cliques of G:

sage: G.cliques_maximal()
[[0, 3], [9, 10], [17], [33, 30]]

I let you benchmark between the two methods and tell us which is better in which cases !

To understand the link between the cliques of the graph G and the simplicial complex C in my previous answer, you can read about "Rips complex".



EDIT : This method works, but there is a Sage bug when the set is made of RDF elements (see the following discussion and trac ticket 14853). Here is a dirty workaround until the bug is fixed: we replace a RDF element by a tuple made of a single RDF element.

sage: A = Set([RDF(0),RDF(3),RDF(9),RDF(10),RDF(17),RDF(30),RDF(33)])
sage: Atuple = map(lambda x:(x,), A)
sage: G = Graph()
sage: G.add_vertices(Atuple)
sage: for u,v in CartesianProduct(Atuple, Atuple):
....:    if u != v and max(u[0],v[0]) - min(u[0],v[0]) <=3:
....:        G.add_edge(u,v)

Then,

sage: C = [[c[0] for c in clique] for clique in G.cliques_maximal()] ; C
[[0.0, 3.0], [9.0, 10.0], [17.0], [33.0, 30.0]]


EDIT : The bug has been fixed in sage 5.12, so you can now use this method as well without having to use the workaround, even with vertices in RDF.