Sparse- and low-rank approximation wiki
Welcome to the sparse- and low-rank approximation wiki. This wiki has information on solvers and problems that arise in these fields (and subfields, such as compressed sensing).
Everyone is welcome and encouraged to edit this wiki; it runs on the same software as wikipedia. Please use common-sense and standard etiquette when editing. The first step to editing is to create an account. For an idea of where to start editing, see pages that are wanted. If you have an implementation of an algorithm, please link to it!
There are many excellent lists of related material on the web. This wiki is not trying to duplicate this information, but rather provide a less comprehensive but more detailed listing of available methods. The goal is that this website becomes a useful tool for practitioners searching for the ideal algorithm, and for researchers wanting to develop new methods.
For new users: when you create an account, please do not include any numbers in your username (or if you really want to, please email us first). There are many spam-bots that create accounts, so the administrators will automatically delete any account that appears to be suspicious, and this includes all usernames with numbers in them.
The contents of this wiki have been organized into categories.
- Problems formulations that arise in sparse- and low-rank approximation.
- Solvers that are used for solving these problems. There are many sub-categories of solvers, such as:
- Benchmarking/Test problems for comparing algorithms
- Applications (in software) of sparsity or low-rank based techniques
- Hardware devices that perform compressed sensing.
- Other resources on the Internet.
If you have ideas for more categories, please go ahead and make them! But please check first to make sure that the new category is really necessary and won't duplicate a similar category.
Want to contribute but not familiar with wiki software?
On this mediawiki software, all versions of a page are stored, so that it is always possible to undo edits at a later time. So have no fear! If you want to add content but do not know how to format it nicely, please go ahead and add the content, and then if necessary, someone else can format it later. We value content over style!
If you see something on the wiki that you like and want to know how to make code like that, then just edit the page to view the source code and then just close the window.
Here are some examples. A link to an external website looks like: [http://www.google.com], which produces 
To be fancier, you can give the link a nicer name: [http://www.google.com google], which produces google
To make internal links in this wiki (which is encouraged!), use the format [[Other resources]], and this produces the link to the page Other resources.
If you want to name the link with a different name, use the format [[Other resources|Other internet resources]] to produce Other internet resources.
To make a bulleted list, start the line with a *. Use # for numbered lists. Use <nowiki></nowiki> to write things that should not be interpreted as wiki code; if you add an empty space before the first <nowiki> then it will make a special box and keep the spacing as you wrote it. Using <tt></tt> or <code></code> gives mono-spaced text like this.
To add a page to a category (say, the "Convex Solvers" category), add [[Category:Convex Solvers]] to the page. If you want to link to the category "Convex Solvers", use [[:Category:Convex Solvers]] which gives Category:Convex Solvers. You can make the link have a nicer name by using the | operator again, e.g. [[:Category:Convex Solvers|Convex solvers category]] gives Convex solvers category.
To add a reference to a paper, there are several ways to you can do it. Here's one good method, which consists of two or three steps.
- Step 1. Add a references section to the page, if it doesn't already exist. It should look like this:
== References == <references> </references>
- Step 2. Add your specific reference to the references section, anywhere between <references>
and </references>. It should be in this format:
<ref name="myPaper">J. Smith, "Name of paper", journal information, [http://arXiv.org link to paper]</ref>
- Step 3. In the main part of the page, wherever you want to reference your reference, add code like:
<ref name="myPaper" />
Linking to the arXiv
We have a special "widget" that makes it easy to link to the arXiv. All you need is the arXiv number. Right now, the widget just inserts a link to the arXiv, but in theory, it could do more (like the authors and abstract could show up in a little box whenever your mouse goes over the link), if someone has the time to write a better widget.
Use the widget by just inserting code like the following:
which produces arXiv:0904.3367.
If you are up to it, you can edit the behavior of the arXiv widget.
There is an even fancier, experimental widget called Widget:ArxivHelper, which tries to give a link with the paper title and authors, and then describe the abstract when you put your cursor over the page. This widget relies on feed2js -- thanks!