User talk:Haseldon

Welcome!

Hello, Haseldon, and welcome to Wikipedia! Thank you for your contributions. I hope you like the place and decide to stay. Here are some pages that you might find helpful:

I hope you enjoy editing here and being a Wikipedian! Please sign your name on talk pages using four tildes (~~~~); this will automatically produce your name and the date. If you need help, check out Wikipedia:Questions, ask me on my talk page, or place {{helpme}} on your talk page and ask your question there. Again, welcome! Oleg Alexandrov (talk) 13:57, 10 February 2007 (UTC)[reply]

Excellent!

Hi there. Really gratifying to see this article expanded so soon after I started it. I've started a number of other similar articles in the hope that this would happen - I've been doing a considerable amount of work on matrix articles and stubs, trying to fill gaps etc, using the List of matrices article as a starting point. So far I've added around 25 matrices and descriptions to it, reorganised it somewhat, mended a few incorrect definitions etc. Unfortunately I just spent about 2 hours trawling through texts on linear spaces and linear operators and such, in the vain hope I might find some useful information to expand some of these, but frankly a lot of these matrices seem to be considered far more by engineers and physicists than they are by mathematicians, and I don't have much in the way of suitable texts here.

If you can shed any further light on any of the articles I've started, please do! Here.

Dan Pope 20:11, 10 November 2006 (UTC)[reply]

Links

Just a note - I noticed in some of your articles, links such as "projection" appear. This should really be "projection" (notice the difference in target but unchanged visible text). In the wiki markup, this is expressed as [[projection (mathematics)|projection]] or [[spectral theory|spectrum]]. Forgive me for the presumption! Dan Pope 01:58, 11 November 2006 (UTC)[reply]

Thanks! Haseldon 16:36, 11 November 2006 (UTC)[reply]

Dispersive PDE Wiki is up for deletion

Hello Haseldon. The above article does not assert notability, and has no references. Do you think you could bring it up to WP standards before the AfD closes? I think it has promise. The deletion debate is at [1]. Reply on my Talk page if you're not familiar with this process. Thanks, EdJohnston 06:05, 17 December 2006 (UTC)[reply]

On 17 December I expanded the very short article, but I may have introduced inaccuracies. Please look at my changes to see if I summarized the Wiki correctly. I have not yet found any introductory material on that Wiki, it seems you already need to be a graduate student in the area. Let me know if I missed something we could point WP readers to. EdJohnston 18:44, 17 December 2006 (UTC)[reply]

Unit matrix

Hi there - would you happen to have a reference for where unit matrix is used? I have always thought that unit matrix and identity matrix were the same...at least, until I came across that article! --HappyCamper 11:37, 21 June 2007 (UTC)[reply]

Hi! Even if I have edited the page, I am neither familiar with the term, and I do not know if it is standard. However, note that "identity matrix" depends on how matrix multiplication is defined. The identity matrix (with 1:s on the diagonal) is related to the "usual" matrix multiplication. However, there are also other ways to multiply matrices. One is the Hadamard product. In this product, the identity operator is represented by the "unit matrix" (the matrix with 1:s in every entry). I added a very short note in the entry about this. Haseldon 13:26, 21 June 2007 (UTC)[reply]