Brian Borchers
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Registered User
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I'm a professor of mathematics at New Mexico Tech, in Socorro, NM. My mathematical interests are primarily in optimization and applications of optimization to parameter estimation and inverse problems, particularly in the earth sciences.
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Mar 26 |
accepted | minimization of a function when the feasible set is an unbounded cone |
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Mar 24 |
answered | minimization of a function when the feasible set is an unbounded cone |
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Mar 5 |
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Proof that polynomial evaluated at roots of unity is DFT Your notation seems a bit confused (and perhaps suggests why you're unable to establish this result.) You haven't explained what $a_{0}$, $a_{1}$, $...$ are. |
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Feb 3 |
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Robust optimization in matlab using fmincon The poster has also put this same question up on scicomp.stackexchange.com, where she's somewhat more likely to get a useful answer, provided that she can clarify the question. |
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Dec 26 |
answered | Projection and Positive matrices |
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Dec 26 |
revised |
Relating the angle between two vectors to max and min eigenvalues deleted 5 characters in body |
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Dec 26 |
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Relating the angle between two vectors to max and min eigenvalues You can think of the $x_{i}^{2}$ as nonnegative weights that sum to one. This opens up the whole world of the generalized mean inequality. |
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Dec 26 |
answered | Relating the angle between two vectors to max and min eigenvalues |
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Dec 16 |
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How to solve a system of linear equations without storing the matrix? If the matrix isn't sparse, and the cost of getting individual matrix entries is large compared to the cost of accessing an element of a matrix stored in conventional dense matrix form, then iterative methods are going to be horribly slow in practice. |
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Dec 16 |
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How to solve a system of linear equations without storing the matrix? Let me clarify what I meant here- "being able to get an arbitrary element M(i,j) at little cost" isn't very useful. If you don't know where the nonzero elements are in the matrix, then you have to check every single one to find the nonzeros. If you do happen to know where the nonzero elements are, and you can compute them quickly, then you could use this as a way to do matrix vector multiplications in an iterative method. |
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Dec 7 |
answered | How to solve a system of linear equations without storing the matrix? |
