Timeline for Is Wishart distance always positive?
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
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| Sep 25, 2020 at 22:09 | comment | added | shaunakde | In PolSAR the C is garunteed to be positive semi-definite and hermitian. With that constrain, this can be used as a distance measure. | |
| Oct 2, 2017 at 13:30 | history | edited | Aksakal | CC BY-SA 3.0 |
add ref to distance properties
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| Oct 2, 2017 at 3:22 | history | edited | Aksakal | CC BY-SA 3.0 |
added 519 characters in body
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| Oct 2, 2017 at 3:13 | comment | added | Aksakal | @sepideh, the formula is correct only because it's the one used in this domain. They call thing thing a distance measure. I bet it's because it's not a sensible distance. It doesn't have any features of the distance, such as subadditivity. It's something that can be used in this classifier | |
| Oct 1, 2017 at 20:47 | comment | added | mdewey | Perhaps edit your new example into the question? | |
| Oct 1, 2017 at 17:15 | comment | added | Sepideh Abadpour | I know it can't be but consider two matrices $A=\begin{bmatrix}0.75 & 0 & 0\\0 & 0.5 0\\0 & 0 & 0.25\end{bmatrix}$ and $B=\begin{bmatrix}0.5 & 0 & 0\\0 & 0.25 0\\0 & 0 & 0.125\end{bmatrix}$ both of them are positive definite. then surely we will have $|A|=0.09375$ and $\ln|A|=-2.3671$ and $A^{-1}B=\begin{bmatrix}0.66 & 0 & 0\\0 & 0.5 0\\0 & 0 & 0.5\end{bmatrix}$ and $\text{Tr}(A^{-1}B)=1.66$ and we will have $\ln|A|+\text{Tr}(A^{-1}B)=-2.3671+1.66=-0.7071\lt 0$. I mean it seems that either the formula in the book is incorrect or I am doing something wrong | |
| Oct 1, 2017 at 17:12 | history | edited | Aksakal | CC BY-SA 3.0 |
added 109 characters in body; deleted 5 characters in body
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| Oct 1, 2017 at 17:10 | comment | added | Aksakal | @Ferdi this answers OP's question. I'm not sure yoy what you mean. | |
| Oct 1, 2017 at 17:05 | comment | added | Ferdi | This does not really answer the question. If you have a different question, you can ask it by clicking Ask Question. You can also add a bounty to draw more attention to this question. - From Review | |
| Oct 1, 2017 at 17:02 | review | Low quality posts | |||
| Oct 1, 2017 at 17:17 | |||||
| Oct 1, 2017 at 16:44 | history | answered | Aksakal | CC BY-SA 3.0 |