Questions tagged [count-data]

Count data are non-negative integers representing whole amounts.

Filter by
Sorted by
Tagged with
2
votes
0answers
41 views

How to forecast low values in data more accurately than the higher values?

I have a scenario where I have to forecast small values in data more accurately than the higher values. I have data set as below ...
2
votes
0answers
34 views

Variable is count total from all clinics within unit that reported cases, some didn't report. How do I deal with this type of missingness?

This is the first time I have posted (but I have read a fair few threads on this site before). This question is quite general in nature since I don't know where to start, or maybe I don't know the ...
0
votes
1answer
20 views

How to interpret the hurdle or zero-inflated model

I have 137 data points that are inspection and I'm trying to find the hurdle negative binomial distribution that fits. Here is how the data looks I have the following code ...
0
votes
0answers
35 views

Including a count data covariate into a 3 way factorial robust ANOVA and outliers in R

I have a three way ANOVA testing the effect of phosphorus (5 rates) x water-logging x cultivar (one water-logging tolerant, one not) on shoot biomass. There are four reps. I'm using R to do the ...
0
votes
0answers
37 views

Time Series Regression

I have count data, some of which forms an exponential decay type distribution and other data sets which are log normal. They are time series and I’m looking to create autoregressive models using first ...
1
vote
1answer
20 views

Compare frequency counts between two groups with 300 observances(variables)

I have a dataset with observations of counts (I've also calculated proportions of the total) between two groups. These observations are essentially on the presence of material types. I'm trying to ...
0
votes
0answers
6 views

How to estimate number of views when supplied with lower and upper limit only, for Poisson-like data?

I'm looking at some Facebook advertising data. It has a row for each ad and the upper and lower bounds of the impressions for that ad (i.e. number of times it was displayed). For example: ...
1
vote
1answer
36 views

Right way to bin the data-Fitting Voigt profiles to spectroscopy data

I have some measurements of the rate of a physical process versus energy. For each energy I have a number of counts and a measurement time associated to it. However, the step (in energy) at which the ...
2
votes
0answers
62 views

Test for significant difference of count data between distributions

I have distributions of counts of DNA segment lengths, and I want to check if a distribution has been significantly increased between "treatments" and across populations. Conceptual example: There ...
1
vote
0answers
32 views

Fish counts and Poisson [closed]

I am having troubles with fitting a Poisson distribution to my data, let me explain: I have fish counts of different species from a closed list, at 5 sites, 2 different depths, and across 10 years. ...
1
vote
1answer
46 views

Why we cannot use linear regression with count data?

We know the counting data can use the Poisson regression or NB regression model, we also know the counting data will violate the normal distribution hypothesis when using Linear regression. I would ...
3
votes
2answers
54 views

Relationship between change in one variable in relation to another

I have on variable that is number of visitors. I am trying to investigate if a recent increase in another variable has caused or related to an increase in the number of visits. I have run some ...
0
votes
0answers
8 views

Fitting a Negative Binomial Distribution to small data set

I would like to perform a sample size calculation based on data from a small pilot study. In this experiment, cells are counted in each individual. There will be two different treatment groups which I ...
0
votes
0answers
14 views

Is aggregated poisson-distributed data still poisson-distributed?

I want to aggregate a dataset which is Poisson-distributed in which each event that occurs is measured at a different time. The data is transformed into transactional data, aggregated on UserID. So ...
0
votes
0answers
20 views

R: Random Forest with count-data: hand it over as a quantitative integer or an ordered factor?

I am using the "rf" method as implemented in the caret package for R. In R you can differentiate between qualitative and quantitative variables. I am unsure how to view count-data. E.g. the number of ...
0
votes
0answers
23 views

Negative coefficients of regressors in arimax,should be positive

I have two years of daily time series inbound call centers data starting from Jan 2018 to Nov 2019. I am doing arimax and regressors are mainly promotional flag along with day of the week (sun, mon ......
-1
votes
1answer
16 views

How to Analyze Frequency Data with Between-Within Factors

I'm trying to analyze data from an intervention study that has 70 participants separated into two groups (Control and Intervention - Between Subjects) and looks at pre-post data (Within Subjects) The ...
0
votes
0answers
27 views

ANOVA with unbalanced sample sizes across levels of the repeated measures factor

I have a design with a group x condition design, whereby some of the repeated measures (conditions) have missing data. Thus, I have, for instance, 10 values at condition A, but only 8 values at ...
0
votes
0answers
26 views

Estimating the uncertainty on a single sample drawn from a Poisson distribution

Consider the following example section of a time series, which shows a continuous signal in voltage, and a discrimination threshold. Each time the signal upwardly crosses the threshold counts as an ...
1
vote
0answers
18 views

Multiple imputation for count data

Date, Transect, Year, Species, Tr.Length, Month, numb.on.transect I am working with historical sea-survey data.... boat transects counting birds on water. only there are some transects ...
2
votes
2answers
109 views

How to measure and visualise relationship between two sets of count data over time?

I have two sets of count data - one for different viral species, and one for different mosquito species. The count data spans 7 weeks, in 3 different locations. I want to be able to show that ...
1
vote
2answers
24 views

Comparing Closeness Between Two Counts

I need to count the number of cells in several pictures. Since the picture is not totally clear, I let two people to count for each picture. I need to compare to see if the two counts are close enough ...
1
vote
0answers
31 views

Using count (instead of proportion) data with cbind() in R… in both dependent and independent variables?

In a study I hypothetically conducted, I have the number of times individuals pressed an "A" button and the number of times they pressed a "B" button. I also recorded the numbers of times they made ...
0
votes
1answer
40 views

How to model count data in which events are not independent

I have data on the number of hospitalizations over one year in patients with chronic obstructive pulmonary disease, and I need to estimate the difference in the number of hospitalization between two ...
0
votes
1answer
49 views

Response is count and the first explanatory is binary second is continuous. Which GLM should I use?

So I've got a response variable with count data e.g. number of species found and two explanatory. The first is a treatment I did or did not applied -> Yes or No, so binary. My second explanatory would ...
1
vote
1answer
30 views

One- vs two-sided credible interval for Poisson process with all zero counts

In a related question, I asked about a confidence interval for the estimate of the mean of 50 observations of a Poisson random variable, for which all 50 observations had a count of zero. In the ...
0
votes
1answer
15 views

Standardizing predictors for Neg Binom Regression

tl;dr: If I include an interaction term in Negative Binomial Regression, should I standardize the predictors? I am analyzing a very large dataset (over 60 million observations) that has the following ...
0
votes
0answers
71 views

how to run a two way ANOVA in excel on summary data: counts of consumers

I have a table of counts of consumers, and I would like to run a 2-way ANOVA on them. There are two factors, year and age-group. Please see the following table of data. Although I usually have ...
0
votes
0answers
28 views

Count Analysis - How to analyze the Impact of a Predictor

Say you have data as shown below and the data represents Incidents of a certain type at a Toll Plaza. The incident count is directly related to the Vehicles Per Day (VPD), so you can calculate the ...
1
vote
2answers
63 views

Means centralization, is it a thing?

Assume a dataset of counts in distances (1, 2, 5, and 10) to a point from three independent samples (a, f, and ...
1
vote
1answer
98 views

Confidence intervals for the mean of a sample of counts

I'm sure the answer to this question is obvious, but I can't seem to find it! How do you calculate the confidence interval around the mean of a sample of counts? I've made an example below in R, ...
1
vote
1answer
73 views

Time series Count-data forecasting in R [closed]

I have sales data shows the number of units sold (so it is a count data). I am evaluating the following models: the lightgbm Count Time Series Following Generalised Linear Models (R tscount library) ...
0
votes
0answers
18 views

From multiple Bayesian BetaBinomial bandits models, to logistic regression

Suppose I have a single categorical predictor $X_1$ with K>2 levels, and a binary outcome Y. We have two objectives, in order of priority: Identify if there is level $k$ in $X_1$ that significantly ...
0
votes
1answer
37 views

Poisson regression for count data that is not Poisson distributed?

Is it true that Poisson regression is used to model count data? But not all count data follow a Poisson distribution? Then you can still use Poisson regression in that case?
1
vote
1answer
81 views

Check if dropout rates are independent for an interaction of two independent variables (one with a large amount of levels)

I am trying to analyse dropout rates in an experiment, but there are multiple issues which collide, and I don't know how to deal with them as a whole. First, find a list of those issues. Below, see a ...
1
vote
0answers
46 views

Pearson Goodness-of-Fit Test

I am trying to compute the Pearson-Goodness-of-fit statistic for Count data to see if the mean and variance are correctly specified. I am using example data from Deb and Trivedi downloaded here: https:...
3
votes
1answer
224 views

Variable selection in zero-inflation models

I am trying to understand how to perform model comparison between different count models. In this example the author performs a zero-inflated poisson model testing the effect of number of people in a ...
0
votes
1answer
26 views

How to test mean differences in proportions that are dependent

I have an experimental setup where I have allowed groups consisting of about 50 animals to select between two environmental conditions. I.e. animals had the possibility to move between the two ...
0
votes
0answers
29 views

Count Data and Relationships

I am new and it was suggested I migrate a question I have over at StackOverflow. I am editing the question to hopefully make the stats question easy to understand (without the noise of code ^_^ ) ...
1
vote
1answer
161 views

Computing different types of negative binomial regression

I want to compare different Count Data Models. How does one compute NEGBIN type I and NEGBIN type II in R? Which model is estimated by glm.nb()? Thanks in advance
1
vote
1answer
21 views

have many error likelihoods, how to combine to get a confidence or p value?

I'm working in bioinformatics and its been a long time since I dusted on my statistics. Basically I'm working on variant calling which amounts to sequencing a large number of sequence reads and ...
1
vote
0answers
54 views

Why do negative binomial regression coefficients differ by level of data stratification and coefficients from Poisson models do not?

I'm trying to understand why regression coefficients from negative binomial models are sensitive to the level of stratification of the data and regression coefficients from Poisson models are not. ...
0
votes
0answers
39 views

Choosing the appropriate test to use when analyzing categorical count data

I am analyzing data that compares responses to various questions across a variety of demographics. I want to see how the count of each response varies by each demographic group. The most basic test to ...
0
votes
0answers
17 views

count data model with capped response variable

I'm trying to predict the total number of Olympic medals won by a country in the summer Olympics games. I have data from 2000 to 2012 relating to the country gdp, population, number of athletes sent, ...
1
vote
1answer
78 views

Kruskal-Wallis and Negative binomial regression do not agree

I am comparing the number of broods made by dung beetles (Brood_Number) across three temperature treatments (Temp_Offset, a 3 ...
1
vote
0answers
21 views

Predicting vector of counts

I was wondering if there are any models that are similar to Poisson regression, but instead of having 1 count as the target, there is a vector of counts as the target. For example: Typical Poisson ...
1
vote
2answers
63 views

Data analysis for counts

What would be the best data analysis to use for the following data? I was thinking of using the Wilcoxin ranked sum but there are so many ties. I have two independent groups and I am just looking to ...
0
votes
0answers
34 views

Dynamic poisson-time series regression

Basically, my question is similar to Time series dynamic poisson regression, yet I didn't get any clue by its answer. I'm modeling dengue incidents with GLM (poisson regression; because the response ...
2
votes
1answer
28 views

Regression with count data as an independent variable

I want to understand the appropriate way to regress a duration variable on a count variable. For instance: I have data on turn around time of a process in a hospital ward. The ward admits patients ...
0
votes
0answers
16 views

Overdispersion under different longitudinal constraints

I have panel data (police districts observed across many months) and I am modeling a count outcome. Fitting a Poisson model (simple pre/post comparison with 6 months of data) results in significantly ...