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| bio | website | |
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| location | ||
| age | ||
| visits | member for | 8 months |
| seen | Mar 27 at 0:00 | |
| stats | profile views | 2 |
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Nov 5 |
answered | Reverse rotation matrix |
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Oct 14 |
comment |
Gently push my non-Positive Definite matrix back into the set of Positive Definite matrices Thank you @joriki I have parallelized my computation of my big matrix to speed up testing ideas and I have formalized my testing. I'm using Mathematica so I'm going to trust its numerical results are as good as I can get. I think the bottom line is I'm stuck with a severely poorly conditioned matrix. I get 408 eigenvalues but I get 405 singular values. My determent is $10^{-1194}$ However, I do get, as you pointed out, a Positive Definite matrix when I re-biuld with $|\lambda|$ |
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Oct 14 |
comment |
Gently push my non-Positive Definite matrix back into the set of Positive Definite matrices Yes I agree something somewhere is going bad most likely in my code. I have played with the essence of small ($3\times 3$) positive-definite matrices testing everything I would expect to be true and I get what I expect. But when I work with my real problem that has a $408\times 408$ and this is a small case, I get unexpected results. I do not what to drag you or anyone into the depths of my code but I'm looking for some silly things to check and think about. |
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Oct 13 |
comment |
Gently push my non-Positive Definite matrix back into the set of Positive Definite matrices I tried taking the absolute value of the eigen-values then re-building but it remained non-Positive Definite. I also made sure that my eigen-vectors were real. |
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Oct 13 |
awarded | Student |
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Oct 13 |
asked | Gently push my non-Positive Definite matrix back into the set of Positive Definite matrices |
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Oct 13 |
awarded | Editor |
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Oct 13 |
revised |
A binomial multiplied by a poisson added 99 characters in body |
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Oct 13 |
awarded | Teacher |
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Oct 13 |
answered | A binomial multiplied by a poisson |
