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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2
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2answers
47 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 ...
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1answer
23 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 ...
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1answer
53 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 $P_X(x < x_0 \mid K, N)$?
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133 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 $b > 0, k > 0, c > 0$. ...
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36 views

Does anyone recognize this probability distribution?

Can someone tell me what distribution/ family of distributions is this?
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36 views

How to choose and plot the most appropriate distribution in R?

I need to choose the distribution that best fits my data for different datasets. There are similar discussions here and here, but I am still struggling to find proper solution. My first attempt was ...
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1answer
42 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}} ...
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0answers
20 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 ...
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0answers
31 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 ...
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1answer
37 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,...
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35 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 ...
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2answers
78 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 ...
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0answers
22 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: ...
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2answers
719 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 ...
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1answer
17 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 ...
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0answers
65 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 ...
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0answers
28 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 ...
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58 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 ...
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0answers
41 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, ...
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0answers
29 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 ...
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1answer
71 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 ...
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65 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 ...
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1answer
318 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 ...
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1answer
223 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 $\Gamma(2,1)$ ($\alpha \to \infty$) ...
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1answer
88 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 ...
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2answers
271 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 ...
3
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1answer
139 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 ...
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2answers
6k 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 ...
3
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2answers
310 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 ...
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0answers
50 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 ...
2
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1answer
73 views

$X_i + X_i^2$ where $X_i \sim$ normal; what is the distribution?

$X_i + X_i^2$ where $X_i \sim$ normal. Does this sum have any particular distribution?
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0answers
22 views

Identifying the best fitting distribution type to test

Hi I tried to analyze a dataset, of USDT concurrency and following is the frequency distribution I received for log return I need this dataset to fit for a particular distribution. Can we suggest ...
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3answers
843 views

How to determine which distribution fits my data set?

I have this data set which I am trying to find which distribution my data set can be accurately represented by using r. I performed the Shapiro-Wilk test and found that my data does not come from a ...
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0answers
41 views

Identifying the distribution of this data

I'm working with a datetime series, and each observation is the count of occurrences per that period. This sounds to me like these values would be Poisson distributed. But my EDA has left me ...
2
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3answers
116 views

How long is a distribution considered normal?

I have a dataset of metric distances ($n=5800$) and plotted those as a histogram. My initial thought was that this distribution looks normal. But after performing a Shapiro Wilk test and plotting the ...
3
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1answer
442 views

Is there a common underdispersed discrete distribution with unbounded support for general mean and variance?

I have a mean $\mu$ and a variance $\sigma^2$ with underdispersion, i.e., $\sigma^2<\mu$. Is there a standard discrete distribution with these moments and unbounded-on-the-right support, i.e., ...
0
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1answer
94 views

What kind of distribution is this?

I'm sorry is this is too obvious, but I'm having a hard time trying to find a distribution for my data. It is clearly not a normal distribution. It does not seem to be skewed, but seems to have fat ...
2
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2answers
97 views

What kind of frequency distribution is this?

I have a discrete frequency distribution, that looks like this I am trying to find what type of distribution is it? I looked at many models but it does not seem to comply with any. I have 345 ...
2
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1answer
123 views

Are the data in this figure normally distributed?

What kind of distribution is figure 2 in this study? If it's a Gaussian distribution for the LH hormone, I can't make any sense of the data. The article: Aksglaede, L. et al. (2009): Recent decline ...
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0answers
56 views

What is the distribution of this Random Variable? I am expecting a Chi-Squared, but there is one term which is extra

I am trying to find the distribution o random variable $H$, but I am somehow confused. The assumption is $M$ and $N$ are large enough (maybe around $100$). When $L=1$, the distribution of $H$ is a ...
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0answers
63 views

Identify the underlying distribution from multiple samples

I have $30$ unequal samples ($n_i >1000$) from a supposedly same population. How should I go about identifying the underlying distribution of the population using these $30$ samples simultaneously? ...
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0answers
27 views

Distribution of relative proportions of draws from two uniform distributions

Drawing samples from 2 uniform distributions and calculating pairwise proportions of drawn values gives rise to a distribution I cannot recognize. What distribution is this? ...
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0answers
140 views

Determining the distribution of data

Hi, I am a student learning financial modelling. I would like some help in determining the distribution of the data given the plots above. I am reluctant to assume normal distribution of the data due ...
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1answer
89 views

Which distribution is this [closed]

I know this will be a f distribution.But it's not f(m,n) since the square sign is outside the summation.So it will be f(1,n).But i can't seem to know how exactly.
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0answers
795 views

If this is a log normal distribution, how can I fit it?

The qualified question title hints at my not being certain as to what I'm really dealing with. I have some truly random samples that generate the following graph. This is just a small extract and ...
2
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2answers
158 views

How to determine the distribution iof this transformed variable $X_c = X ({1_{\{|X|>c\}}}-{1_{\{|X|\le c\}}})$

I have one question from econometric class which asks to find the probability distribution of the following: $$X_c = X ({1_{\{|X|>c\}}}-{1_{\{|X|\le c\}}}) $$ where $X \sim N(0,1)$ and $c > 0$...
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0answers
74 views

Is this a known distribution?

For work, I plotted a set of shops by how many times they did business in the past week. The plot I got out looked something like this: This looked obviously like a Pareto distribution. After all, ...
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1answer
138 views

KS, Anderson-Darling and Cramer -Von Mises don'y work on these data . Why? [closed]

I am using Mathematica to model the distribution of the data below and I test the fits with AD, CVM and KS but none of them seems to work I was told that my data may have an excessive amount of ties. ...
4
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2answers
2k views

How to determine the type of probability distribution for a dataset?

I have aggregated(total) youtube videos views. I have take log of that views. And calculated autoregressive koefs that can be used for the video views predictibility tests. Let say I have aggregated ...
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0answers
55 views

Looking for a good distribution to analyse market dynamics

I'm experimenting with replacement for normal distribution for my models. So far, I tried Gamma and Inverse Gamma distributions. Gamma significantly underestimates the probability of the extreme ...