Timeline for Is a sample covariance matrix always symmetric and positive definite?
Current License: CC BY-SA 4.0
19 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Feb 5, 2023 at 8:44 | review | Suggested edits | |||
| Feb 5, 2023 at 10:25 | |||||
| Jan 19, 2022 at 4:56 | comment | added | user3180 | y does not have the be non-zero. It can be any y | |
| Nov 6, 2018 at 16:09 | history | edited | Zen | CC BY-SA 4.0 |
deleted 3 characters in body
|
| Nov 6, 2018 at 15:43 | comment | added | an offer can't refuse | Since the rank of $[z_1, z_2, \cdots, z_n]$ is less or equal to $k$, the condition can be simplified to the rank is equal to k. | |
| Oct 22, 2018 at 3:51 | history | edited | Zen | CC BY-SA 4.0 |
deleted 89 characters in body
|
| S Apr 6, 2018 at 0:34 | history | suggested | CommunityBot | CC BY-SA 3.0 |
corrected definition of the sample mean
|
| Apr 5, 2018 at 21:20 | review | Suggested edits | |||
| S Apr 6, 2018 at 0:34 | |||||
| Jul 11, 2017 at 21:43 | history | edited | Zen | CC BY-SA 3.0 |
deleted 5 characters in body
|
| Apr 30, 2013 at 4:46 | history | edited | Zen | CC BY-SA 3.0 |
added 7 characters in body
|
| Apr 28, 2013 at 18:47 | history | edited | Zen | CC BY-SA 3.0 |
added 9 characters in body
|
| Mar 24, 2013 at 19:37 | history | edited | Zen | CC BY-SA 3.0 |
added 6 characters in body
|
| Mar 24, 2013 at 17:43 | vote | accept | Morten | ||
| Mar 24, 2013 at 5:55 | history | edited | Zen | CC BY-SA 3.0 |
deleted 93 characters in body
|
| Mar 24, 2013 at 4:57 | history | edited | Zen | CC BY-SA 3.0 |
added 71 characters in body
|
| Mar 24, 2013 at 4:33 | history | edited | Zen | CC BY-SA 3.0 |
added 619 characters in body
|
| Mar 24, 2013 at 4:11 | history | edited | Zen | CC BY-SA 3.0 |
added 103 characters in body
|
| Mar 24, 2013 at 3:41 | history | edited | Zen | CC BY-SA 3.0 |
deleted 546 characters in body
|
| Mar 24, 2013 at 3:26 | comment | added | whuber♦ | I like this approach, but would advise some care: $Q$ is not necessarily positive definite. The (necessary and sufficient) conditions for it to be so are described in my comment to Konstantin's answer. | |
| Mar 23, 2013 at 22:50 | history | answered | Zen | CC BY-SA 3.0 |