A distribution is a mathematical description of probabilities or frequencies.

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Fitting an exponential distribution to data and finding third quartile problem

I have a data-set with range of 0 to 1. I'm fitting a distribution to it in MATLAB using ...
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30 views

Exponential distribution hypothesis testing

I want exponential distribution hypothesis testing with MATLAB. Is any test or method for that?
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47 views

What is name of this distribution and can we have 68–95–99.7 rule for it?

I have a distribution like this: What is name of this distribution? As you know we have 68–95–99.7 rule in ...
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40 views

Normal Distribution with random mean and standard deviation

When trying to code this in R, I'm getting very confused about what to do. Apologies if my terminology is incorrect but I would be grateful for any advice. The Problem: I have been given two normal ...
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88 views

What is meant by categorical distribution?

Is this separate type of distribution (EX: Binomial,bernoulli, Multinomial) or any distribution can be represented by this way. Can someone elaborate with simple example
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234 views

Common name for distributions that are bounded on one side

Is there a common name to refer to distributions that are bounded on one side, and unbounded on the other side? For example, log-normal distribution, where the minimum value is zero, the maximum is ...
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'Extrapolate' a probability density to a different support

here is my scenario: I have N triangles and N probability distributions (of independent variables), and the support of the ith probability distribution is just the ith triangle. The triangles may ...
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27 views

Am I using the correct model, if so what do I need to fix?

I am seeking to model the number of high tunnels on farms with 13 other factors. Factors include: lattitude, percent of the population with food access, percent of vegetable acres per county, ...
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35 views

Finding the most “uniform” or “least concentrated” density function, subject to moment constraints

Background I want to find a probability measure for a continuous random variable, subject to moment constraints, that is maximally "uniform", as defined below: Definition: Maximally Uniform ...
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1answer
21 views

References to papers/books that uses a kernel to smooth a discrete distribution

Since a kernel, such as Gaussian, is often used to smooth out the distribution of discrete points in 1D, 2D or 3D, I believe there must be some study materials or research work that have used this, ...
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26 views

How to apply Gaussian kernel to smooth density of points on 2D (theoretically)

I have a set of discrete points on a 2D surface and need to build a heat map or a distribution of the density of the points. However, I also need to smooth out the density/distribution by applying ...
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39 views

Relative increase between two pairs of samples

Consider the following samples from four distributions: $a = \{20, 2, 200\} \qquad\qquad c = \{1, 10, 100\}$ $b = \{22, 2.2, 220\} \qquad\quad\:\,d = \{1.2, 12, 120\}$ I would like to say that the ...
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18 views

Distribution of distances to an observation from the normal and the median of these distances

Given $x\sim \mathcal{N}(\mu=0, \sigma^2=1)$, the squared distances of the $x$ values to $\mu$ are distributed $\chi^2_1$. I am interested in the distribution of the squared distances to an arbitrary ...
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69 views

How to statistically compare groups for multiple density plots?

Is there a statistical method to compare these density plots other than ANOVA (MANOVA)? I would like to compare the densities among year within each plot and report which of those distributions are ...
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53 views

Can I use Kolmogorov–Smirnov test on my Data?

I am not good in statistics so I desperately need your help. So I have this dataset of distributions, and I want to know if I can use the KS-test on it. the Idea is saying that the feature's ...
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19 views

Distribution comparison across different treatments

if I have a table like this In which, site = different sites of measurement (tissue or organ) type = different types of virus And I want to ask something about the data 1.What test can I use to ...
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Human movement distribution [closed]

I need help with the mathematical distributions to use to model user movement (user travel pattern) in a city or a given geographical area. I don't have any data; my question is limited to theoretical ...
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34 views

Is there a PDF for a generalized non-central chi-squared distribution [duplicate]

Is there a PDF for a distribution defined as a sum of squares of random variables pulled from a family of normal distributions with different standard deviation? Is there a way of analytically ...
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36 views

Can ayone help me in solving the below Problems of probability distribution?

Patients arrive randomly and independently at a doctor's surgery from 8·0 A.M. at an average rate of one in Five minutes.The waiting room holds 2 persons. What is the probability that the room will be ...
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Bayesian probabilty [migrated]

I need to know how to find the Bayesian probability of two discrete distributions. For example the distributions are given as follows: ...
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162 views

Determining probability distribution for datasets with missing values

As a part of my exploratory data analysis (EDA) prior to further analysis, I'm trying to determine a probability distribution of my pilot dataset's variables. A particular feature of this dataset is a ...
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61 views

Determining beta distribution parameters $\alpha$ and $\beta$ from two arbitrary points

Suppose I have two points $(p_1,x_1)$ and $(p_2,x_2)$ where $p_i$ is a probability on the beta CDF and $x_i$ is a value on that same CDF. How would I go about determining the beta distribution shape ...
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Automatic identification of distribution of data

Some statistical tools offer methods of automatic identification of the distribution of data, such as the one shown in this post. Generally, is this approach reliable? If not, what's a better ...
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How to find the distribution of the weighted sum of independent Bernoulli random variables for positive non-integer weights

How do I find the distribution of the weighted sum of independent Bernoulli random variables if the weights are non-negative real numbers? I have N number of independent Bernoulli distributed random ...
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Have Narrow Distribution - Need Standard Distribution

I am building a model in R using GLM based on this predictor variable. As you can see, the data is concentrated in the center of the distribution, and then falls off sharply. Is there a ...
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25 views

Acceptance rejection method for a binomial distribution

I have a R-code for acceptance rejection method for a beta-distribtuion but would like to use it for a binomial(30, 0.4) distribution instead. Here is the code: ...
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29 views

Get the distribution of a dataset

this is a conceptual question. In data mining, the problem often arises that scientists/data engineers are using an expert guess for the underlying distribution of their data. Often their assumption ...
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91 views

Normalization to non-degenerate distribution

I am reading de Haan's Extreme Value Theory (2006). In the discussion of distribution of sample maximum, he said "in order to obtain a non-degenerate limit distribution, a normalization is necessary". ...
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Comparison between MAD and SD

I am reading Huber's Robust Statistics (2nd). On page 2 and 3 he gave an example. The basic facts are summarized here. Let $(X_n)$ be a sequence of random variables and define two measures of spread ...
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How to determinate standard deviation above and below mean classes programatically

I have an array of float from wich I calculate the mean and the standard deviation. The user can specify a number of class varying between 2 and 8. The min and max values of each class is calculated ...
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71 views

How many eligible bachelors in a city?

This is a very simple question posed to me by a friend of mine. I know it's a statistical analysis problem, but I suck at math. Given the total population of $x$ within a metropolitan area, what ...
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34 views

How to take cumulative sum of a 2D distribution?

How can I take the cumulative sum of a 2D distribution, starting from the highest value in the distribution? Background: my 2D distribution is the probability of different combinations of wave ...
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24 views

What is the difference between dexp and pexp [duplicate]

I understand probability distribution but I am having a hard time getting a grasp on probability density function, specifically difference between dexp (density of exponential distribution) and pexp ...
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19 views

How to describe a distribution of statistics in a meta-analysis?

I'm conducting a meta-analysis using water-quality data collected from multiple lakes in multiple regions. Due to the differences in the sampling programs, each waterbody has been sampled an unequal ...
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sample generative model from a chain/tree

I have a tree of states and I would like to sample from this tree based on pure birth process; however, I don't know how exactly I can do this; so far I have done this; I simplified my problem; the ...
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Cumulative distribution function: what does $t$ in $\int\exp(-t^2)dt$ stand for?

I'm trying to teach myself how to quickly translate many different types of equations into VB, T-SQL and MDX code. Since I'm trying to build a skill, not just solve a single isolated problem, I'm try ...
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31 views

How does Standard Deviation (Error) change with sample size change in this scenario. Explanation needed for a nonprofessional

I have this question that I want figured out. A person's Blood pressure was taken 4 times,the mean of these 4 observations came out to be say 120mm of Hg And the SD was 2.5. Now we have taken 4 more ...
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34 views

Test means of populations with lots of zeros, is sampling the way to go?

I am trying to test whether means of two populations with lots of zeros are different. Here is the following python code example: ...
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Best distribution to handle a ratio of counts as a response variable

A quick statistics question (apologies for the added biology): I have two sets of counts (for the expression of two different isoforms of a particular gene), and to generate the response variable in ...
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Generating hyperbolic variates

How do you simulate from the hyperbolic distribution? The Wikipedia article on it does not describe how to do so. I know that the hyperbolic distribution is a special case of the generalized ...
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1answer
33 views

Distribution of (maximum) run length

I am curious about the distribution of (maximum) run length given k independent trials when $p(X=1)=p_1, p(X=2)=p_2, ..., p(X=n)=p_n.$ For example, for a coin tossing for 3 independent trials, ...
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How to best plot a heavy vs light tailed distribution in R

I want to create a plot that overlays a heavy vs light tailed distribution as an example and am trying to figure out the best way to do this. I can plot gamma distribution which is light tailed and a ...
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How do I compute the density of this data set that is made up of two different 3D-distributions?

A sequel to this question. I have a dataset where: $\frac{4}{5}$ of the points are drawn from: $(x, y) \sim \mathcal{U}_{2}(0,30)$, $(z) \sim \mathcal{U}_{1}(14.5, 15.5)$. $\frac{1}{5}$ of the ...
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Will I go to UC Berkeley?

I forget where I got this data (I think from About.com College), but here are some statistics regarding University of California, Berkeley admissions: the 25th percentile SAT Reasoning Test score was ...
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What is the correct notation if two random variables belong to the same distribution?

I want to explain that both the real and imaginary part of a complex variable follow a zero-mean complex Gaussian distribution. How can I write that? For one variable I'd write $a \sim ...
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Finding distribution function [duplicate]

Let $X_1,X_2,...$ denote iid random variables such that $X_1$ is continuously distributed with density $p(x)$ and distribution function $F(x)$ where $F(0) = 0, F(x) > 0$ for all $x > 0$, and ...
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54 views

Multivariate normal distribution has peaks

I'm trying to calculate a bivariate normal distribution in matlab(with mvnpdf), but the pdf I obtain has a strange shape with several peaks. This is the code I use: ...
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27 views

Mean and variance of a general multivariate skew normal distribution

I have a problem about a general multivariate skew normal distribution. There is a $p\times 1$ vector, $\mathbf{y}=(\mathbf{y}_1',\mathbf{y}_2',\ldots,\mathbf{y}_n')',p>n$, which has the density as ...
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how calculate inflation observed and expected p-values from uniform distribution in QQ plot

I am trying to quantify degree of inflation (ie. how best the observed data points fit to expected). One way is too look at QQ plot. But I would like to calculate some numeric indicator for inflation ...
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23 views

Simple measure for comparison of rainfall regularity

In meteorology we have the concept of monthly rainfall, which is just the sum of daily rainfall over that month. Now, given this extreme example: Situation 1: ...