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Questions tagged [poisson]

Poisson is a discrete probability distribution in statistics that is popular in probabilistic modeling (including in Bayesian statistics) as well as business forecasting.

Poisson is a discrete probability distribution in statistics that is popular in probabilistic modeling (including in Bayesian statistics) as well as business forecasting. It is given by the formula for a random variable $X$:

$$P(X = k) = {{\lambda^{k}e^{-\lambda}}\over {k!}}$$

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Poisson distribution, Standard deviation, fitting line

Let's say I have system A, B, C, and D. Each system contains 10,000 numbers generated by Poisson distribution. The difference is the mean is different for different systems. I calculated the std dev for each distribution corresponding to each…
Surya
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MLE for Poisson conditioned on multivariate Gaussian?

I am writing some Python code to fit 2D Gaussians to fluorescent emitters on a dark background to determine the subpixel-resolution (x, y) position of the fluorescent emitter. The crude, pixel-resolution (x, y) locations of the pixels are stored in…
olympiader
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Difficulty understanding the difference between Poisson, Quasi-Poisson, and Negative Binomial models

I will try to keep this short. As an assignment for my GLM course, we were given a dataset on the # of homicide victims a person knows, as well as the race of the person. The main idea is to answer the scientific question "Does race help explain how…
Ali Shana'a
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How to implement large-scale Poisson Regression in Python

I am trying to implement a Poisson Regression in Python to predict rates. I am dealing with a ton of data (too much to store in a DataFrame), which means that using the standard statsmodels.api GLM Poisson Regression won't work. I know that sklearn…
Michael Petro
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Poisson model with overdisperssion

I'm working with a dataset $X$ (of length $N$) of count data, which looks like: I developed a statistical model which can be improved, so I'm asking for any suggestions, for instance, differnet likelihoods or prior selection, different approach,…
ignatius
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Is there R functions that allow to test for overdispersion when fitting a model with survey design?

I realized I need to use the package survey to be able to include sample weights in my regression analysis. Initially, I wanted to use a negative binomial regression on each one of my outcomes as count data is more often than not overdispersed, so I…
airpoll_epi
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regression by grouping the dependent variable

I have a large dataset exploring the effects of the independent variables on the dependent variable using Poisson regression since the dependent variable is a count variable. However, the range of the dependent variable is too large. Hence, I was…
tempx
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How can I obtain the mean of a Poisson distribution given the first improbable point of the distribution?

I generated a Poisson distribution with mean equal to 3 and 10000 samples by using np.random.poisson(3,10000). The plot is the following: from this plot I see that given the mean equal to 3, a point like 12 is very unlikely to fall into the…
HelpNeederStudent
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