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Questions tagged [quantile-function]

For questions related to the so called quantile function of a cumulative distribution function or generalized inverse of a cumulative distribution function.

0 votes
1 answer
64 views

If I have a measure $\nu$ on $\mathbb{R}$ and $G_\nu$ is its quantile function, i.e. the generalised inverse of the cumulative distribution function $F_\nu$. I'm trying to show that for any $s\in\...
bosh111's user avatar
  • 57
1 vote
1 answer
121 views

This theorem is from Capinsky and Kopp's book on measure theory. Theorem: If a function $F : \mathbb{R} \to [0, 1]$ satisfies the following conditions (i) $F$ is non-decreasing i.e. $y_1 \leq y_2$ ...
TryingHardToBecomeAGoodPrSlvr's user avatar
3 votes
1 answer
292 views

(Skorokhod's representation theorem): Let ${X_1,X_2,\dots}$ be a sequence of real random variables, and $X$ a further random variable. Then ${X_n}$ converges in distribution to ${X}$ if and only if, ...
shark's user avatar
  • 1,883
4 votes
1 answer
182 views

The cumulative distribution function of the standard normal distribution $\Phi(z)=\displaystyle\frac{1}{\sqrt{2\pi}}\int_{-\infty}^z e^{-t^2/2}dt$ cannot be expressed in terms of elementary functions, ...
m-stgt's user avatar
  • 585
0 votes
1 answer
52 views

I'm trying to compute the general case of inverse of CDF of $Y=X^2$, where $Y,X$ are random variables. Given that a CDF $F_X$ is a strictly increasing function, also has to be it's inverse. The CDF $...
Daniel Muñoz's user avatar
3 votes
1 answer
145 views

Problem 21.1 of the book 'Asymptotic Statistics' by Aad van der Vaart reads the following Suppose that $F_n \to F$ uniformly. Does this imply that $F_n^{-1} \to F^{-1}$ uniformly or pointwise? Give a ...
Stan's user avatar
  • 213
1 vote
1 answer
233 views

I am thinking about the consequences of adding prediction intervals and the consequence it has on the resulting interval. For example, I am considering when to expect the sum of two such intervals to ...
Galen's user avatar
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1 vote
0 answers
86 views

Consider a random variable on $\mathbb{R}$ that may or may not have an expectation. (E.g., if its pdf is a Cauchy distribution, it won't.) Let $p(u)$ be a probability density function on $\mathbb{R}$. ...
HW.'s user avatar
  • 53
1 vote
0 answers
43 views

I’ve encountered following problem: Let $X$ be a positive random variable with distribution $P^X$, cumulative distribution function $F_X$ and quantile function $q_X$. Show that $$E(X)=\int_0^\infty1-...
Papillus's user avatar
1 vote
0 answers
71 views

Let $F$ be a CDF with $f\equiv F'$ having a positive support (edit), i.e. $\text{supp}(f) \subseteq \mathbb{R}_+$. Then $Q\equiv F^{-1}$ is its quantile function and $q\equiv Q'$, where we know $q(p) =...
John Ritz's user avatar
0 votes
2 answers
66 views

According to Wikipedia, the quantile function is defined by $$Q(p)=\inf \{x\in\mathbb{R}:F(x)\geq p \}.$$ But if I apply this to equally likely data set 10, 11, 12, 13, I get $Q(0.5)=11$. But shouldn'...
ashpool's user avatar
  • 7,528
0 votes
1 answer
220 views

I assume $X\sim\mathcal{N}(\mu,\sigma)$ and wish to sample values but I am confused about different approaches and concepts that seem to be relevant for this problem. It appears to me that this ...
Ronnie Marksch's user avatar
2 votes
1 answer
177 views

Suppose that $f(x)$ is a smooth probability density function on $\mathbb R$ and denote by $a_i$ the $\frac{2i-1}{2n}$-th quantile of $F$ for $1\leq i \leq n$, where $F(x)$ is the cumulative ...
Fei Cao's user avatar
  • 3,018
2 votes
0 answers
71 views

Consider the convex cone of quantile functions of random variables on the real line (with finite second moment), that is $$ C := \{ Q_{\mu}: \mu \in \mathcal P_{(2)}(\mathbb R) \}, $$ where $Q_{\mu}(p)...
ViktorStein's user avatar
  • 5,054
5 votes
1 answer
136 views

While pondering Wasserstein-2 gradient flows of the Kullback-Leibler divergence functional $\text{KL}(\cdot \mid \nu)$, where $\nu \sim \mathcal N(0, 1)$ is the standard normal distribution (yes, I ...
ViktorStein's user avatar
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