A discrete distribution defined on the non-negative integers that has the property that the mean is equal to the variance.

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Can we use the AIC values to compare a hurdle poisson model to a multinomial logit model?

I estimated two different models using an SP survey: Hurdle poisson and multinomial logit with 5 alternatives. My dependent variable is the number of weekly trips (0,1,2,3,4,5 trips) that students ...
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14 views

how to construction glm poisson , which is y and x to be used in R [duplicate]

The Independent newspaper tabulated the gender of all candidates running for election in the 1992 British general election (Table 2: The gender of candidates in the 1992 British general election ...
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1answer
36 views

how to construction glm poisson Y and X [on hold]

The Independent newspaper tabulated the gender of all candidates running for election in the 1992 British general election (Table 2: The gender of candidates in the 1992 British general election ...
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0answers
18 views

poisson distribution probability [closed]

probability that a car will have a flat tire while driving through a tunnel is 0.00007. Use the poisson distribution to approximate the probability that among 10,0000 cars 1 will have a flat
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2answers
71 views

Suppose that $X\sim\text{Poisson}(\lambda)$, find $E[X(X-1)(X-2)(X-3)]$

Hint: do not use linearity, use definition of expectation. i have a rough idea that we turn the inside into g(x), but not sure how to proceed from there.
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1answer
44 views

Convert Poisson distribution to normal distribution

I primarily have a computer science background but now I am trying to teach myself basic stats. I have some data which I think has a Poisson distribution I have two questions: Is this a Poisson ...
3
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1answer
112 views

Find the parameter of a Poisson, given the distribution function at a known value

Assuming a Poisson distribution, the probability ($\alpha$) that the result will fall within the range $0\ldots k$ is given by the following expression: \begin{equation} \alpha = ...
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1answer
23 views

The probability of a student getting a given question correct and the associated uncertainty (Item response theory)

I'm doing some statistics on multiple choice test scores (with item response theory, (http://en.wikipedia.org/wiki/Item_response_theory). I want to know the probability that a student with a certain ...
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0answers
7 views

How to determine CDF of Poisson function when only arrival time and service time are known?

If I can sample any given poisson arrival and service rate at any point and can sample any no of times. How just out of that sampling can I determine the CDF.
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1answer
29 views

to find the values of gamma distribution knowing the parameter value of a poisson

I have a variable X, and information available to me is that the parameter $\theta$ is around 2.2 $X\sim \mathbf{Poisson}(\theta)$ How can I determinate the value of the parameters $\alpha$ and ...
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2answers
35 views

Poisson as a limiting case of negative binomial

I was reading "Maximum Likelihood Estimation for the Negative Binomial Dispersion Parameter" by Walter W. Pieogorsch, and in the intro it says the Poisson distribution is a limiting case of negative ...
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27 views

Is there a Poisson-Gamma-Gamma model?

An example to elucidate my problem: The total claim amount can be modelled by a Poisson-Gamma model as it is assumed that the events (e.g. accidents) are Poisson distributed and the claims are Gamma ...
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1answer
119 views

Poisson process and the memoryless property

I understand that inter-arrival times of a Poisson process are exponentially distributed and therefore the inter-arrival times are memoryless. However, how about the waiting times of Poisson process ...
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2answers
25 views

Testing for independence between variables in poisson distribution

I'm trying to figure out how to test if variables that I think follow a Poisson distribution are independent (which is a requirement of the Poisson distribution) -- or it it matters. Let's assume I ...
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0answers
12 views

Values for the parameters of a Gamma in a Gamma-Poisson distribution

I need values for the parameters $ \alpha,\beta$ of a Gamma distribution that represent the parameter $\theta$ in a Poisson distribution,so its expected value. I'm using these distribution to ...
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0answers
49 views

Count data in a Structural Equation Model

I am currently trying to fit a structural equation model (SEM) on a certain dataset using R (lavaan package). Some of the most important variables in my model are count data (abundance of different ...
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1answer
36 views

Find out if I can ask for more

Scenario: I have a system that issues requests to another system. Each of these requests have a probability $p$ of requiring a specialized resource. The probability $p$ can be estimated using a ...
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1answer
27 views

Distribution of sum of two shifted Poisson

Suppose Y is shifted Poisson at "a", say Y -a ~Poisson (t) and X-b ~ Poisson (r), again a shifted Poisson at "b." Now what is the distribution of Z= X+ Y? Any idea? How to prove it?
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53 views

Poisson regression

I'm analyzing an article for my studies with the hypothesis if a change in work motivation is related with a change in mental well-being (http://www.sciencedirect.com/science...01879113001541). Sadly ...
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35 views

Glm with Poisson in R with no p-value?

I've been doing glm and thought I had it cracked but looking at some sites for interpreting results I realised R had displayed my results oddly. ...
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0answers
13 views

Poisson confidence interval that accounts for time?

I've gathered Poisson-distributed data and would like to compute a confidence interval, but the number of events and the amount of time are very small. Since standard CIs for rates aren't appropriate ...
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1answer
63 views

Correct Poisson Distribution Formulation

I have a Poisson formulation with the following parameters: I see 90 people in a city an hour 1.2% of people in the city are Indian How would I calculate: The maximum amount of time before I ...
3
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1answer
46 views

Use law of total variance to find unconditional variance of overdispersed Poisson?

First, I need to prove that the distribution of a RV X, where X|lambda ~ Pois(lambda), and lambda ~ gamma(a, B), is a negative binomial. I know that it is, but why negative binomial instead of another ...
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38 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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33 views

R: Is it possible to estimate the poisson noise?

I have a dataset of many discrete counts (RNAseq read counts per base), which contain both real signals and background noise. The noise is random, and should be poisson distributed. What I would ...
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2answers
57 views

Mean of Poisson distribution experimentally

Suppose I approximate a variable (events of certain type) by a Poisson distribution and I would like to write a program and measure the mean experimentally. The idea is that I have an algorithm which ...
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1answer
40 views

Credit Risk and Concentration

I am working with a UK credit-union and we are looking to build a model to assess our credit risk and changes to this over time. We have a number of loans to borrowers who each have a credit rating ...
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2answers
47 views

Call Centre Models

Can anyone suggest me, which Mathematical(Statistical) methods can be used to predict incomingcalls by a given time interval at a call centre? Please cite any ...
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40 views

Bivariate Poisson regression: Error: “in `contrasts<-`(…): contrasts can be applied only to factors with 2 or more levels ”

I realize this error message has been posted before, but the solutions previously provided does not work for me, so here goes: I am working with a data.frame, which looks like this: ...
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57 views

Analysis of Split (A/B) tests using Poisson and/or Binomial Distribution

I've seen this question asked before, but I have yet to come across a definitive source answering the specific questions: What's the most appropriate statistical test to apply to a small A/B test? ...
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24 views

Using glm(family = guassian) on data that is actually Poisson. Strange non-symmetrical bias

Let's say I want test the consequences of assuming a normally distributed response variable in a glm model when it is really Poisson. I simulate some data with some quadratic terms. ...
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63 views

Statistic for count process and measurements

I am facing some problems concerning which statistical approach to use for my measurements. I have a sensors which counts how many times an events occured. I had to characterize two lots of sensors, ...
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72 views

Count data correlation

My dataset is basically a time series - each case is a one day and several events are being observed for each case. I am not experienced in time series analysis but I still would like to get at least ...
2
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0answers
60 views

Basic idea of zero inflated two part models(hurdel) and application to big data (machine learning)

I'm currently working on the data which has 90% 0s in response variable. Based on my research, it seems zero inflated models could be a solution to this. However, while I was reading related ...
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1answer
68 views

Choosing cutoffs in examining the Poisson distribution (an application to prime numbers)

I have observed a number ($n=6$) of events and want to test the null hypothesis that they are Poisson distributed with a known parameter $\lambda\approx1$. But I don't know exactly when I started and ...
3
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1answer
64 views

C-Test for comparing poisson means in Scipy

I'm relatively new to stats, and I have a large dataset of strings (n=114541) for which I'm interested in a binary event: whether X occurs or not (specifically, whether a specific language construct ...
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4answers
657 views

How odd is a cluster of plane accidents?

Original question (7/25/14): Does this quotation from the news media make sense, or is there a better statistical way of viewing the spate of recent plane accidents? However, Barnett also draws ...
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1answer
120 views

Particle filter (sequential Monte Carlo) for a non-Gaussian hierarchical model

I have the following, which I am attempting to model with a particle filter. \begin{align*} y_{i,t}&\sim\mathrm{Poisson}\left(\lambda_{i,j,t}\right)\\ ...
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3answers
476 views

How is the poisson distribution a distribution? It seems more like a formula

I just watched this video: https://www.youtube.com/watch?v=Fk02TW6reiA It shows a formula to calculate an answer for the following problem: There are 2 customers expected every 3 minutes in a store ...
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2answers
35 views

Count event using Poisson random variable

An event occurs with a mean of 15 times per hour and a standard deviation of 10 times/h. From the population a sample of 100 individuals is drawn. What is the probability that the sample mean will be ...
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1answer
85 views

Is it Poisson distributed, and if so, what's its meaning?

I've collected data from my website. The website is about cars. The data are about user reviews and the cars. what we see in the graphs is the probability of some car type (Ford Focus 2008) to have X ...
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200 views

Deriving the bivariate Poisson distribution

I've recently encountered the bivariate Poisson distribution, but I'm a little confused as to how it can be derived. The distribution is given by: $P(X = x, Y = y) = ...
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1answer
80 views

Poisson Regression Residuals

I'm modeling the number of doctor visits (a count variable) on factors such as income, chronic condition, insurance, etc. I use the canned Stata command ...
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34 views

Estimating a distribution from a dataset with multiple parameters

How would you go about solving the following problem? You're an insurance company who writes workers compensation policies. You want to build a probability distribution for the number of annual ...
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3answers
108 views

Confidence interval for poisson distributed data

I'd like to calculate the confidence interval for a variable with a lower bound and I can't seem to figure out how to do so. I've seen several similar posts, but none answered my question, at least ...
2
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0answers
27 views

power of poisson test with large sample size

I would like to compute the power of two distributions which are poisson with $n_1$ being large and $n_2$ being medium sized. I have used the formula given by Krishnamoorthy and Thomson for the C-test ...
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55 views

Estimation parameters for latent (unobserved) variable

Here is my problem: I have 3 variables $X,Y,Z$ : $X$ is the number of clicks we observed on an web advertisement; $Y$ is the number of time a customer do a sign-up on the website after clicking ...
3
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3answers
67 views

Test for aggregation of binary events/successes (binomial/glm??)

this has been vexing me for a while and I can't seem to solidify an answer beyond vague thoughts about Poisson distributions. I think this is a simple problem and I'm missing something obvious. Any ...
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1answer
66 views

Problems with Poisson Regression

I have been studying a linguistic construction (let’s call it C) in a language L1 trying to individuate several factors (...
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15 views

Vanishing coefficients with poisson model in glmnet

The other day I made a poisson model in glmnet using the averages of observations over a 1 year period to predict a count. The result was pretty good, but I figured it could be made better by binning ...