2
votes
2answers
63 views
Computing equivalent vector of random variables from covarience matrix
Given a covariance matrix, how can I construct a vector of expressions of randomly distributed variables whose covariance matrix is equal to the given one?
I have an algorithm tha …
0
votes
1answer
109 views
Why is Beta the maximum entropy distribution over Bernoulli’s parameter?
Why is Beta(1,1) the maximum entropy distribution over the bias of a coin expressed as a probability given that:
If we express the bias as odds (which is over the support $[0, \i …
1
vote
3answers
132 views
Is any bias introduced from initial clustering
I hope this is an appropriate forum for this question, and I asked on math.stackexchange as well. If it doesn't belong, I don't mind closing this. If my questions is not clear, p …
1
vote
3answers
185 views
Is ERNIE output skewed by statistical tests?
ERNIE is a hardware random number generator used to generate winning Premium Bond numbers in the UK. Wikipedia says: "ERNIE's output is independently tested each month by an indepe …
8
votes
2answers
437 views
Bounding sum of multinomial coefficients by highest entropy one
When does the following hold?
$\sum_{(i_1,\ldots,i_k)\in E}
\frac{n!}{i_1! \ldots i_k!}
\le \exp(n H^*)$
Where
$H^*=\max_{(i_1,\ldots,i_k)\in E} -(\frac{i_1}{n}\log \frac{i_1}{ …
3
votes
1answer
99 views
Random, Linear, Homogeneous Difference Equations and Time Integration Methods for ODEs
Most methods (that I know of) of numerically approximating the solution of ODEs are "general linear methods". For this type of method, the so-called 'linear stability' is examined …
0
votes
1answer
92 views
Kernel width in Kernel density estimation
Hi,
I am doing some Kernel density estimation, with a weighted points set (ie., each sample has a weight which is not necessary one), in N dimensions.
Also, these samples are just …
1
vote
1answer
125 views
sum of order statistics
Suppose I have N real random variables with identical PDF. At every instance of these r.vs, I pick $K$ largest out of $N$. Lets call their sum as $S_K$. Alternatively, based on …
0
votes
1answer
167 views
The density of x_1^n+x_2^n where x_i are Gaussian
We define a process $\chi_k^n=\sum _{i=1}^k x_i^n$ where x_i are iid gaussian processes.
I try to find the distribution of $\chi_k^n$. If k=1 then we get $f(x^n=y)=\frac1n y^{\fra …
0
votes
0answers
73 views
Using Fisher Information to bound KL divergence
Is it possible to use Fisher Information at p to get a useful upper bound on KL(q,p)?
KL(q,p) is known as Kullback-Liebler divergence and is defined for discrete distributions ove …
1
vote
0answers
63 views
Multinomial transformation for matrices
Suppose we have a vector of probabilities $\mathbf{p}=(p_1,...,p_n)$, where $p_i>0$ for $i=1,...n$ and $\sum p_i=1$. Define new vector $\mathbf{r}=(r_1,...,r_{n-1})$ in a followin …
1
vote
1answer
96 views
Maximal inequality over two indices
In Freedman's series of 3 books on Markov processes, I find that I keep on running into terms like:
P[$\max_{0 \leq s \leq 1, s \leq t \leq rs}$ | B(t) - B(s) | > $\epsilon$]
in …
1
vote
0answers
73 views
What will be the distribution of harmonic mean of two correlated gamma random variables?
Suppose there are two correlated random variables $X_1$ and $X_2$ both are gamma distributed but having different shape and scale parameters with correlation coefficient $\rho$. Wh …
3
votes
2answers
72 views
Relation between regularities of the trajectory of a mean zero gaussian process and its covariance operator
Let $\xi_t$ be a zero-mean gaussian process on $[0,1]$ with covariance operator $C$.
I would like to better understand the relation between the covariance operator and the regular …
0
votes
0answers
34 views
estimating mean (and st dev) of a truncated gaussian curve without spike
http://mathoverflow.net/questions/21347/estimating-the-mean-of-a-truncated-gaussian-curve assumes that we know how many of the non-positive values are observable. How can this be e …

