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I love mountainbike. I hate the Matrix Cookbook.
Jan 15 |
revised |
Solving a matrix equation $X=c \cdot AXA' +I$ with a diagonal corrections
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Jan 15 |
answered | Solving a matrix equation $X=c \cdot AXA' +I$ with a diagonal corrections |
Jan 14 |
revised |
How to calculate the square root of matrix $A+B$ perturbatively?
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Jan 14 |
revised |
How to calculate the square root of matrix $A+B$ perturbatively?
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Jan 14 |
revised |
How to calculate the square root of matrix $A+B$ perturbatively?
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Jan 14 |
answered | How to calculate the square root of matrix $A+B$ perturbatively? |
Jan 13 |
answered | Compute adjugate matrix over commutative ring |
Jan 10 |
comment |
Distinct determinants of circulants
$a(1)=1,a(2)=2,a(3)=3,a(4)=3,a(5)=5,a(6)=6,a(7)=9,a(8)=11,a(9)=15,a(10)=19.$ The values are exact until at least $n=12$. Thus this sequence is not in oeis.org/A215723 |
Jan 10 |
comment |
Distinct determinants of circulants
@ Turbo , let $a(n)$ be the number associated to $n$. $a(11)=23,a(12)=59,a(13)=56,a(14)=111,a(15)=223,a(16)=258,a(17)=361,a(18)=880,a(19)=1161,a(20)=2327$. Since I use a random research, the true value of $a(n)$ is $\alpha$ (the value which is given above) or $\alpha +1$ or $\alpha +2$. |
Jan 10 |
comment |
Distinct determinants of circulants
@ Turbo , according to numerical experiments (until $n=17$) the number of distinct absolute values seems to be at least $O(n^2)$. |
Dec 5 |
answered | Calculating the dimension of the algebra generated by some given matrices |
Dec 1 |
revised |
Rank 1 Approximation of Elementwise Inverse Matrix
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Dec 1 |
answered | Rank 1 Approximation of Elementwise Inverse Matrix |
Nov 28 |
comment |
Resolvent of a triangular matrix
In my mind "no kidding"="is it a joke ?", that is about the Michele's sentence: " where $p_A$ is the characteristic polynomial of $A$, which is easy to compute once we know an eigendecomposition of A"; that is funny when one knows that $A$ is a triangular matrix. This seems to me absolutely innocuous. Compare with "Récoltes et semailles", the book written by Grothendieck; at least, read the introduction (chapter 0). |
Nov 28 |
revised |
Resolvent of a triangular matrix
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Nov 27 |
revised |
Resolvent of a triangular matrix
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Nov 26 |
answered | Resolvent of a triangular matrix |
Nov 26 |
comment |
Unitary factor in polar decompositions
@ Lin , I don't think so ; yet even if $-1$ is never an eigenvalue, that does not imply that $C_n<2$ because $C_n$ may be a LimitSup. |
Nov 26 |
answered | Characterizing space that preserves positive-definiteness property |
Nov 25 |
revised |
Unitary factor in polar decompositions
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