Timeline for An equality involving matrix multiplication
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 1, 2016 at 16:19 | vote | accept | man_in_green_shirt | ||
| Jan 1, 2016 at 14:49 | comment | added | David Simmons | No, it's not natural notation - don't get used to it. Natural notation is to have $\mathbf{x}_i$ denote a column vector. I think the author has chosen this odd use of notation to ensure the reader (watcher) is aware that the object being considered is a transposed column vector of some sort ... maybe ... I'm just guessing really ... | |
| Jan 1, 2016 at 14:46 | comment | added | man_in_green_shirt | So $\mathbf{x}_1$ is actually the transpose of the first row, so that when you take $\mathbf{x}_1^T$ you get the first row? Doesn't look like the most natural notation to me, but I guess I'll get used to it | |
| Jan 1, 2016 at 14:42 | comment | added | David Simmons | I think the $\mathbf{x}_i^T$'s should actually be the rows of $X$. | |
| Jan 1, 2016 at 14:28 | answer | added | Jendrik Stelzner | timeline score: 1 | |
| Jan 1, 2016 at 14:18 | history | asked | man_in_green_shirt | CC BY-SA 3.0 |