Could someone please add a little bit of information on what purpose the direct addition of 2 matrices serves?
Merging Matrix subtraction
The direct addition of matrices should be described under a new entry supermatrices. However, this entry does not exist, possibly because of a lot of coding it would require. I was contemplating to undertake this task, but I am used to the equation editor used by Microsoft and do not know how to add horizontal and vertical lines inside of a matrix in the Wikipedia equation editor. Cruise 16:37, 20 August 2005 (UTC)
- If the direct addition of matrices would be relocated into the (yet nonexistent) entry supermatrices, then matrix addition and matrix subtraction could be either merged, or edited as to correspond to each other. Cruise 16:37, 20 August 2005 (UTC)
I finally started to write the supermatrices entry. It was not so difficult as I initially thought. Chuck, please reconsider your request to merge matrix addition and subtraction. With new additions they form the traditional sequence
- matrix addition
- matrix subtraction
- matrix multiplication
- matrix inversion
Thank you for your understanding.
Cruise 01:14, 21 August 2005 (UTC)
Addition of matrix elements vs. addition of matrices
Addition of matrices and addition of matrix elements are two distinct operations that must have distinct operands. The "usual" addition of matrix elements is more an algebraic than the matrix algebra operation. The "true" matrix algebra operations are typified by the matrix multiplication with the characreristic combination of matrix elements assembled into a composite. For that matter, the similar distinction can be made in the case of matrix multiplication, where you can multiply matrix elements or you can multiply matrices. David Cruise 16:30, 3 February 2006 (UTC).
I removed my contributions as they infringe copyright of Cruise Scientific David Cruise 06:51, 24 July 2006 (UTC)
- I've put a see also for it in. Not sure if anything else should be done here. The article could definitely do with a good citation. Dmcq (talk) 15:31, 24 October 2011 (UTC)
- Um, you're right. This article also refers to the direct sum. Have to think about this. Dmcq (talk) 15:35, 24 October 2011 (UTC)
- Okay put in a stub section that references Kronecker sum. Dmcq (talk) 17:43, 24 October 2011 (UTC)
Vote: should direct sum and Kronecker have subsections on this page?
Please weigh in on whether or not you believe the Kronecker sum and direct sum should have subsections on this page. I believe they should not, as they are altogether different than matrix addition, and just happen to be related to matrix addition by the word 'sum' in their names. There are pages for them elsewhere, https://en.wikipedia.org/wiki/Direct_sum and https://en.wikipedia.org/wiki/Kronecker_product#Kronecker_sum I believe we should add a tag at the top of Matrix addition that says something to the effect of "For direct sum, see (this link). For Kronecker sum, see (this link)."
Since this would be a major change to the article as it now stands I would like to hear input from other editors. Please respond with either yes, that you would like to see Kronecker sum and direct sum removed from the page, and only mentioned in a tag near the top, or no, you believe they should have subsections in the page, as they now do.