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Questions tagged [distribution-identification]

Questions about recognizing a probability distribution from a figure, formula, or text description. Please use a specific, informative title.

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Altiplano distribution---Distributions very flat around the center?

(This comes from a Facebook post, reference at the end) "Everybody knows" that the function $x \mapsto \exp\left(-1/x^2 \right)$ is infinitely differentiable, but not (real) analytic, ...
kjetil b halvorsen's user avatar
1 vote
0 answers
64 views

Is this the CDF of a known probability distribution?

Consider the following cumulative distribution function over $\mathbb{R}^{+}$ $F\left(x\right)\;=\;1+\mathcal{W}\left(-e^{-1-x}\right)$ where $\mathcal{W}\left(\cdot\right)$ is the Lambert W function. ...
bbecon's user avatar
  • 101
1 vote
1 answer
28 views

Estimating the Distribution of the data

I wanted to know the distribution of some discrete points and they don't follow any particular distribution according to the graphical and other methods. So, I thought of applying non-parametric ...
user avatar
0 votes
0 answers
43 views

What distribution has CDF $\propto \psi ^{(1)}\left(x^{-\frac{1}{2}}\right)$

Is there a way to express random variable with the following CDF $g(x)$, $x\ge 0$, in terms of known named distributions? $$g(x)\propto \psi ^{(1)}\left(x^{-\frac{1}{2}}\right)$$ where $\psi^{(k)}$ is ...
Yaroslav Bulatov's user avatar
5 votes
1 answer
242 views

What is this distribution called by?

I have pdf of a continuous distribution as below $$f\left(x\right)=\frac{1}{\sqrt{2 \pi x^3}} e^{-\frac{1}{2} {\left( \frac{x-\mu}{\mu \sqrt{x}} \right)}^2}$$ Is there any specific name for this ...
Bogaso's user avatar
  • 871
1 vote
2 answers
78 views

What kind of distribution might this be? [closed]

I have ran a series of experiments on a theoretical system. For a relatively small number of runs (~30) the data is normally distributed, but for longer runs (~200), a tail develops on the right... ...
HVW's user avatar
  • 63
5 votes
1 answer
82 views

Which distribution is it?

I recently came across the following distribution $$ \Pr(X\le x)=e^{\tfrac{1}{a}-\tfrac{1}{x}}\left(\dfrac{a}{x}\right)^{\tfrac{1}{a}},\; 0\le x< a, $$ and the cdf is 0 for all $x\lt 0$ and 1 for ...
Jeff's user avatar
  • 313
2 votes
1 answer
252 views

Distribution of the ratio of dependent non-central chi-square random variables

I am working on a problem that is similar to the one discussed in this link. But in my case $X_i \sim \mathcal{N}(1, \sigma^2)$, i.e., $X_i$ is not a zero-mean Gaussian RV. Specifically, I want to ...
Mani Bharathi Pandian's user avatar
0 votes
0 answers
59 views

Thoughts on a distribution

I've been having trouble figuring out an appropriate distribution for this data. I wanted to ask for any thoughts. I have percent incidence data (0-100%; not integers) for disease. Using ...
Cole Baril's user avatar
0 votes
0 answers
1k views

Simulate skewed distribution

I want to simulate a left-skewed distribution in R similar to this one: I can do it with rbeta ...
PaulCrebs's user avatar
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4 votes
1 answer
161 views

Does the density $g(y) \propto (1-y^2)^{(n-3)/2} e^{\delta y} \quad\text{for}\quad |y| \leqslant 1$ have a name?

The following probability density function has a particularly simple form, and it was produced when deriving a confidence interval for $\frac{\mu}{\sigma^2}$ , $$g(y;\delta)=c_\delta(1-y^2)^{(n-3)/2}e^...
Graham Bornholt's user avatar
0 votes
0 answers
31 views

What are the name of this distributions appeared on bitcoin trades data?

I have been playing with some bitcoin data that i download from binance API the data correspond to 1min klines there is 1 million of samples that start from 01/08/2020 to 01/02/2022 if i make a ...
Bender Robot's user avatar
2 votes
1 answer
521 views

How to identify the distribution for regression models

I am trying to analyze hunting harvest data with response-variable being individuals/1000 hectares and a series of explanatory variables to describe it. Response variable is continuous (fractionals), ...
Erik Berg's user avatar
5 votes
1 answer
144 views

Name of a distribution similar to the exponential

for a simulation I'm using the continuous distribution $$F(x)=1-(1+x)e^{-cx} $$ for $x\geq 0$ with $c\geq 1$. Do you know if this distribution has a name?
Jo R's user avatar
  • 331
1 vote
0 answers
319 views

Distribution of sum of independent but not i.i.d. lognormal variables?

I am trying to find the distribution of the following variable Z: $X_i$ are each independent with Lognormal distribution ($\mu_i, \sigma^2_i$), $X_i \in L^2$ forall $\forall i$ Z = $\sum_i cX_i$ where ...
mathcomp guy's user avatar
1 vote
0 answers
44 views

Does this distribution with polynomial tails have a name?

I have $N$ random variables which are identically and independently distributed with complementary CDF: $$Pr[X \geq x] = \frac{a}{X} + \frac{b}{X^2}$$ for $x \geq 1/2 \sqrt{a^2 + 4 b} + a/2$. This ...
Asterix's user avatar
  • 359
1 vote
0 answers
79 views

Name of this distribution?

Does anyone know the name of this distribution? What I'm showing below is a likelihood function, given some data points, x1,...,xn, where x can have values like 0, 1, 2,... $f(x|\theta)=\theta(1-\...
Shravan Vasishth's user avatar
-1 votes
1 answer
76 views

What type of distribution does this most closely resemble?

What type of distribution does this most closely resemble? I was thinking that this graph didn't really resemble any type of distribution.
Deanelle Thompson's user avatar
2 votes
0 answers
70 views

Is it possible to have a set of variables as exposure in a causal DAG?

I am working on identifiablity of a test (target) distribution based on the training distribution using interventional graphs. generally, I am wondering is it possible to consider a set of variables ...
Amin Kaveh's user avatar
1 vote
0 answers
62 views

Are there technical terms to describe this non-normal distribution?

This question is about visual inspection of normality. An example of my variable is shown below. This is aggregated Likert scale data (n = 2000). By visual inspection, the data has some sort of bell-...
Coloane's user avatar
  • 165
3 votes
2 answers
193 views

Fitting a distribution like exponential but with always negative $\frac{d^2}{dx^2} \log \text{pdf}(x)$

I have some continuous data in the domain $[0,\infty]$ which I have physical reason to believe is almost, but not quite exponentially distributed. The difference between my idea of a distribution and ...
Sideshow Bob's user avatar
  • 1,485
1 vote
1 answer
44 views

What is the name and formalism of this discrete distribution? [closed]

I am searching the name of something similar to a binomial distribution, but with individual probabilities (P(1) to P(N)). I calculated (brute-forced with a script) the probability of k positive ...
KaPy3141's user avatar
  • 787
0 votes
1 answer
55 views

What distribution is $P_X(x \mid K, N) = \frac{1}{ ( 1 + N)^K} {x + K -1 \choose x} \left( \frac{N}{1+N}\right)^x$?

What kind of distribution is the following: $$ P_X(x \mid K, N) = \frac{1}{ ( 1 + N)^K} {x + K -1 \choose x} \left( \frac{N}{1+N}\right)^x $$ and how can I find $P_X(x < x_0 \mid K, N)$?
Astra Uvarova - Saturn's star's user avatar
3 votes
0 answers
183 views

What distribution has the p.d.f. of form $\frac{e^{-b \cdot x} \cdot x^c}{1 + e^{-k \cdot (x+a)}}$ for $x >0$ and parameters $b > 0, k > 0, c > 0$?

In my work I met the p.d.f. of form $$p(x) \propto \frac{e^{-b \cdot x} \cdot x^c}{1 + e^{-k \cdot (x+a)}}$$ with support $x \in [0, +\infty)$ and positive parameters $b > 0, k > 0, c > 0$. ...
Piotr Semenov's user avatar
1 vote
1 answer
51 views

Let $f_X(x)= \frac{x^2e^{-\frac{x^2}{2}}}{\sqrt{2\pi} } 1_{(-\infty,+\infty)}$, what is this distribution called?

Let $$f_X(x)= \frac{x^2e^{-\frac{x^2}{2}}}{\sqrt{2\pi} } 1_{(-\infty,+\infty)},$$ is the pdf of random variable $X$. What is this distribution called? I only know $f_X(x)\propto x^2e^{-\frac{x^2}{2}} ...
M.F's user avatar
  • 11
0 votes
0 answers
31 views

Help selecting a correct distribution for this data

I'm a geologist working with some sparse borehole data. The boreholes sample igneous intrusions and we're trying to fit a distribution to the thickness of the intrustion vs frequency (for use in other ...
8556732's user avatar
  • 101
1 vote
0 answers
34 views

What probability distribution would be look like this?

I was playing with R, I started with adding consecutive binomials (the n parameter of the second binomial variable depends of the result of the first binomial and so on...). After a few more ...
Albert Beton's user avatar
1 vote
1 answer
40 views

Help finding the type of distribution

I am doing a question which involves the following probability density function $$f(x;\mu,\lambda) = \sqrt{\frac{\lambda}{2\pi x^{3}}} exp\bigg(\frac{-\lambda(x-\mu)^2}{2\mu^2x}\bigg), x>0, \lambda,...
user avatar
1 vote
0 answers
38 views

What the type of distribution may mean?

Some time ago I crossed paths with a textbook that had a whole back chapter on this subject. I loaned it to a co-worker and it went missing. The book was for modeling and simulation people who were ...
BSD's user avatar
  • 235
0 votes
0 answers
63 views

What distribution could the data stem from?

From checking the histogram of the distribution I had the intuition that the data could follow a Poisson or an exponential distribtuion. However, Lilliefors test that the data is exponentially ...
Santiago Cepeda's user avatar
3 votes
2 answers
107 views

Estimating the blockchain mining time for $N$ nodes

I am trying to simulate a set of times for the below problem. There are N nodes. Each node generates a random number($R$) in the range $[0,K]$ per second. Guess the time it takes by each node to ...
SlowMountain's user avatar
0 votes
0 answers
25 views

Test for statistical distribution

I'm new to statistical analysis and I'm trying to identify which distribution fits my BD better. My BD has length of stay (LOS) data in two different hospitals: ...
user avatar
11 votes
2 answers
851 views

What kind of distribution does this have?

Currently I'm trying to figure out the distribution of the following: $X \sim \frac{\sqrt{n}}{\sqrt{Gamma(n,\beta)}}$ where the denominator follows a $Gamma(n,\beta)$ distribution. I've checked out ...
BonnieKlein's user avatar
2 votes
1 answer
251 views

calculate mean of normal distribution given SD and probability corresponding to a single range

Suppose that I have a normally distributed variable with unknown mean and known SD: $X \sim N(\mu, 1)$. I also know that $P(-2 < X < 2) = 0.3.$ Is it possible to calculate $\mu$ from this ...
user697473's user avatar
0 votes
0 answers
69 views

Is there a way to find a statistical distribution for the below data?

Is there a way to find a statistical distribution for the below data? This is derived from frequency count of different topics in a large corpus of news stories. I wonder if this follows a Poisson ...
Gecko's user avatar
  • 109
2 votes
0 answers
32 views

What's the name for a distribution where at the extreme there are more values farther away from the mean than closer?

The image below from this blog provides a good example. I'm talking about distributions that are roughly Gaussian except that there are more values at the high end that would be expected. In ...
jss367's user avatar
  • 408
0 votes
0 answers
167 views

QQ plot distribution check

I want to check if a distribution is log normal or not by using qq plot. So for convenience I am creating a lognormal distribution using stats and checking it in ...
akki_buoy's user avatar
0 votes
0 answers
103 views

Are there any methods to test whether a data set obeys a certain probability distribution?

If one has a set of data, are there any methods or techniques of testing whether that set obeys a candidate distribution? I have thought of a number of possibilities: Simply histogram and look at it, ...
user27119's user avatar
  • 328
0 votes
0 answers
34 views

How can I identify an unfamiliar cumulative distribution function?

I have 116 Bessel-corrected sample variances (average of squared distances from sample mean), each from a sample of three measurements. All measurements were done using the same method. I had ...
MCC's user avatar
  • 67
4 votes
1 answer
79 views

What is the name of this distribution?

I came across this: a categorical distribution with $K=10,000$ parameters (categories), and we take only few samples from this distribution, say $N=400$ (the point is $N < K$). Now, obviously, not ...
John Deterious's user avatar
7 votes
2 answers
663 views

Identifying the following distribution

I have a distribution, which I initially assumed to be a Rayleigh, but it almost certainly isn't. Before I consider convolutions of various distributions, e.g. Rayleigh convolved with Boltzmann, ...
user27119's user avatar
  • 328
1 vote
0 answers
72 views

How can i find a suitable distribution that fits my data?

I have some data on prevalence of a given infection, provided for each country for 6 different age groups. I am trying to find a suitable distribution that may be suitable to model capture the ...
medst254's user avatar
1 vote
1 answer
1k views

Compare distribution to given shapes to find the most similar

I have a multiple comparison problem between some thousands of correlation distributions and given shapes. I have computed pair-wise correlation for a given set of gene expresion data, and I have ...
Emilio Mármol Sánchez's user avatar
12 votes
1 answer
239 views

Name for a distribution between exponential and gamma?

The density $$f(s)\propto \frac{s}{s+\alpha}e^{-s},\quad s > 0$$ where $\alpha \ge 0$ is a parameter, lives between the exponential ($\alpha=0$) and $\Gamma(2,1)$ ($\alpha \to \infty$) ...
nth's user avatar
  • 806
2 votes
1 answer
97 views

Identifying a distribution

I am trying to understand what sort of distribution is produced by the following code. Using the following Matlab code we can generate a distribution (normalized such that the sum of the set is equal ...
Merin's user avatar
  • 77
6 votes
2 answers
442 views

Can anyone suggest a distribution for this histogram

I have some data and I am trying to identify its distribution. The nearest I can get is a skewed-Gaussian distribution, but I don't think it is. The data itself consists of 130000 points and is binned ...
user27119's user avatar
  • 328
3 votes
1 answer
152 views

Name this distribution!

While looking for a link function for my model I realized I cannot find a good fit for the distribution of my Y (see fig. below). It is the distribution of number of offspring for a given season, the ...
have fun's user avatar
  • 266
11 votes
2 answers
19k views

Understanding the Cullen and Frey plot

I would like to figure out which distribution fits my data best. Here is the histogram of my data : I used the fitdistrplus package in R to try to find the best ...
Louna_DO's user avatar
  • 111
3 votes
2 answers
872 views

What does the distribution of bootstrapped values in this Cullen and Frey Graph tell me?

I am trying to find a suitable distribution to describe my data, and as one of the first few steps I created a Cullen and Frey Graph using the descdist command from ...
John Silver's user avatar
0 votes
0 answers
210 views

To what distribution it's similar? Looks like an exponential but it's not

To what distribution it's similar? Looks like an exponential but it's not. It's seems to have a property, that if I zoom it (xlim) then each time it has the same ...
Michael D's user avatar
  • 765