981 reputation
721
bio website vzemlys.wordpress.com
location Vilnius, Lithuania
age 33
visits member for 3 years, 8 months
seen Aug 14 at 10:03

* denotes convolution, $\cdot$ denotes multiplication

I am the developer of the midasr R package:

and you cand find me on


Jul
2
awarded  Curious
Dec
14
awarded  Yearling
Oct
5
comment Dual space of $C_b(X)$
I would try to get this book: books.google.lt/books/about/…,
Oct
5
comment A problem about the quadratic form $x^TAx=0$.
Usually it is assumed that matrix $A$ is symmetric when we are talking about the quadratic forms. For symmetric matrices the statement holds.
Oct
5
comment Solving system of linear eqaution in special cases
Others pointed out that $A=ee^T-2I$, I just wanted to mention that this kind of matrix looks like Householder transformation which is well known and even was named among 10 top algorithms of 20th century.
Oct
5
comment A problem about the matrix equation $a^{\sf T}A_1a=0$.
@Wei-ChengLiu if quadratic form $a^TBa=0$ then $B=0$. We can write any symmetric matrix as $B=P^TDP$, where $D$ is the diagonal matrix. Then $a^TBa=0$ for all $a$ is equivalent to $a^TDa=0$ for all $a$ and then it is clear that $D=0$. The comment of egreg applies to my older version of the answer, where I made some incorrect claims.
Oct
4
comment A problem about the matrix equation $a^{\sf T}A_1a=0$.
I've removed the offending statement. We can show that $a^T(\alpha A_1+\beta A_1^T)a=0$ for all $a$ and all $\alpha$ and $\beta$, but only for $\alpha=\beta=1$ the matrix $\alpha A_1+\beta A_1^T$ is symmetric and we can invoke the quadratic form property.
Oct
4
revised A problem about the matrix equation $a^{\sf T}A_1a=0$.
remove the incorrect statement
Oct
4
answered A problem about the matrix equation $a^{\sf T}A_1a=0$.
May
8
awarded  Caucus
Jan
10
comment Example of atlas for sequence space
@JacobSchlather, yes, open is desirable. But any example would do.
Jan
10
asked Example of atlas for sequence space
Jan
9
comment Regression with arbitrary norm
Have you tried using general optimisation algorithm?
Dec
20
accepted Given collection of sets how to turn it to collection of disjoint sets?
Dec
20
comment Given collection of sets how to turn it to collection of disjoint sets?
@MichaelGreinecker thanks for spotting this, I've clarified the question. I already got the answer, I needed.
Dec
20
revised Given collection of sets how to turn it to collection of disjoint sets?
clarify the question
Dec
20
asked Given collection of sets how to turn it to collection of disjoint sets?
Dec
14
awarded  Yearling
Sep
25
revised Recursive curve fitting
Minor appearance fixes
Sep
25
comment Recursive curve fitting
do you observe $f(x)$ for $x=1,2,...,n$?