Questions tagged [discrete-data]

Refers to data generated from a distribution that has a countable sample space. Discrete data may be nominal (e.g. the distribution of race in a sample of individuals) or ordinal (e.g. the number of errors on a page of text).

Filter by
Sorted by
Tagged with
1
vote
0answers
8 views

T-test for a discrete variable on a ratio scale

I have 20 students that take a test of 25 questions. I record the number of questions each student got correct (e.g., Sam = 10, Sarah = 13, etc.). My 20 students then take the test again a month later ...
0
votes
2answers
37 views

Test fit of discrete data distribution to normal distribution

Here are some grades. (They aren't test scores. They aren't a sample.) I want to test whether a normal distribution derived from the mean and variance of the grades provides a good fit for the grades. ...
1
vote
1answer
32 views

Within sample and between sample categorical variation

I don't really know the correct terminology to ask this question well, so bear with me. I have categorical data with counts and I want a measure of how "diverse" or "spread out" the data is. Variance ...
1
vote
1answer
43 views

Variance (maybe?) of categorical data

I don't really know the correct terminology to ask this question well. I have categorical data with counts and I want a measure of how "diverse" or "spread out" the data is. Variance comes to mind, ...
0
votes
0answers
18 views

“Compressing” or downsampling a discrete probability distribution

I have a discrete probability distribution $P$ which I obtained by applying a softmax transformation, with an automatically-derived exponent $-\beta$, to a set of measurements (potentially large, in ...
0
votes
1answer
27 views

How to make SalePrice as a discrete value?

The target variable, Saleprice originally is a continuous value. I calculated ...
1
vote
1answer
22 views

Probability density function and distribution from samples to population

Heya got a small doubt here most of the discrete random variables utilize simple examples of situations like 3 coin toss or 2 dice rolls or girl/boys born. These examples are simple in the sense that ...
0
votes
1answer
29 views

a question about sampling

I was reading a paper and there was some confusing statements about the sum of two discretized independent random variables. So if X can get m values and Y can get n values then Z = X + Y could get m*...
0
votes
0answers
21 views

Fitting data to a distribution that appears lognormal without right-hump

I will like to fit a distribution and extract its moments in Python, given Length of Stay (LOS) data in hospitals. Asking out of curiosity, suppose the plot of the data looks like: The reason why I ...
1
vote
1answer
37 views

Where does the constant “B” come from in moment generating fuctions?

In my book "Mathematical Statistics with Applications" by Dennis Wackerly it's stated that the moment generating function exists if The moment-generating function m(t) for a random variable Y is ...
0
votes
1answer
28 views

What distribution would be suitable for this (discrete & ordinal) data?

I have a memory experiment where on each trial, a 7 letter scrambled word is presented, and after a delay the participant is shown the intact word and has to type the previously seen scrambled word ...
0
votes
0answers
8 views

What kind of discrete limited dependent variable regression do I need? Or other?

I have a sample of 78 scientific articles plus 385 software and data resources used by these papers. Each paper has between 1-26 such resources. Sometimes, the creators of software/data will request ...
0
votes
1answer
25 views

Correlation between discrete and continuous data

I would like to caculate the correlation between two vectors. One vector represents the intensity of an emotion as continuous data between 0 and 100. The other vector represents the intensitiy of an ...
0
votes
0answers
16 views

Is is possible to estimate a mixed logit model with only individual specific parameters?

I am analyzing some data and I do not have any alternative specific variables in the dataset. The question is about the preference between taxi, uber and automated vehicle if all three have the same ...
0
votes
0answers
50 views

Interpretation of marginal effects multinomial logit R

I'm not really sure how to interpret marginal effects when calculated with mlogit and effects function from R Here is the code ...
0
votes
0answers
15 views

Kullback-Leibler divergence Loss With different-length vectors

I am new to KL Divergence Loss (and indeed all similar comparisons between discrete series data). The output of my network produces a series of tuples of a length that varies during training. The ...
2
votes
2answers
45 views

Applying TF/IDF to non-text data?

I have a classification problem in which I am supposed to predict the end state of an object based on a set of events it experiences. There are about one thousand possible events and each object is ...
1
vote
1answer
33 views

Linear regression vs contingency table for poll results

Let's assume we made a survey where participants had to evaluate us from 1 to 5. We want to analyse how different variables (let's say gender or age for instance) have an effect on the answers. As we ...
1
vote
1answer
200 views

Python: compare 2 discrete distributions

Lets say I have a population consisting of items A, B, and C. I dont know the distribution ...
0
votes
0answers
27 views

Correlation between discrete and binary variables

I have a binary variable representing happiness. This variable can take binary values of 0 (not happy) and 1 (happy). I have another discrete variable representing valence (representing if emotion is ...
3
votes
3answers
75 views

How to test for statistical difference for discrete data

I'm designing an experiment to evaluate reagents used to develop fingerprints. There will be a variety of objects with different surfaces, 2 different reagents, 3 different fingerprint donors (prints ...
1
vote
1answer
77 views

Discretization simulation of a Wiener Process

I got some problems with this homework which I have totally no idea, never got into this field before and I really need some help. First, we have a wiener process like Which means the probability of ...
2
votes
1answer
63 views

Checking assumptions for Mann-Kendall trend test

I have a data on counts of images submitted with requests overtime. I would like to test the null hypothesis of no trend vs alternative hypothesis that there is a downward trend. My data is a ...
0
votes
1answer
34 views

nested logit with individual level fixed effect (panel data)

As is stated in the title, I have several questions concern the combination of nested logit and panel data. 1, Can we run nested logit with the individual fixed effect? this is useful when one has ...
0
votes
1answer
18 views

Fitting a continuous normal distribution to an incomplete score distribution

Given a sample of data that contains only the score frequency distribution for scores below a certain threshold, is it possible to fit a complete normal distribution so to estimate what the will be ...
0
votes
1answer
29 views

What is the best approach to transform scale from 1 to 10 into three categories?

I want discretize my attributes according to the class quality which is the output variable. quality ranges from 1 to 10 in my ...
2
votes
1answer
85 views

Levels of measurement and discrete vs continuous random variables

In psychology studies the levels of measurement of variables that are investigated limit/influences the statistical tests that should be performed such as explained here: https://www....
4
votes
2answers
610 views

Can the discrete variable be a negative number?

I read in a book "An Introduction to Statistical Concepts [3 ed.] p.8): A numerical variable is a quantitative variable. Numerical variables can further be classified as either discrete or ...
1
vote
1answer
46 views

How to estimate the probability mass function of a discrete variable from moments

Consider a bounded, discrete random variable $X$ whose range is $(0,1,\ldots, M)$. We are given the first $k$ moments of this distribution, call them $m_1, \ldots, m_k$. We are interested in ...
0
votes
0answers
17 views

How to predict how many customers are going to purchase based on population purchase frequency?

I am trying to calculate a metric "frequency of purchase of a customer" to determine when I would expect a customer to then purchase an item next. Say, the distribution of my customer base looks like ...
0
votes
0answers
18 views

How to determine the longitudinal duration of effect of one time series on another?

I have two time series related to app usage: Notifications- a time series of notifications sent to the user from the app. User Activity- time series of the user interaction on the app. I am trying ...
0
votes
2answers
61 views

How to evaluate $\mathbb{P}(XY=a)=\mathbb{P}(X=\frac{a}{Y})$, when $X$ or $Y$ take multiple values?

Assume $X,Y$ are discrete and have a finite outcome space. How to evaluate $\mathbb{P}(XY=a)=\mathbb{P}(X=\frac{a}{Y})$, when $X$ or $Y$ take multple values? Does one write out the result for each ...
0
votes
2answers
51 views

Approximate discrete probability distribution

I have a discrete probability distribution with can take a large number of discrete values, say $x \in \{1,\ldots,N\}$. I know $p(x)$ for all these $x$. Typically, quite many of the values have a ...
1
vote
1answer
33 views

Question about continuous and categorical variables

We have 211 measurements of iron and carbon export rates across 5 sites and 2 temperatures, and each of those 5 sites has its own discrete set of physical and chemical characteristics. Would it be ...
0
votes
1answer
33 views

Using `glm()` in R for correlated count data (data provided)

I have data from one group ($n = 25$) of subjects pre- and post- tested on an $15$-item dichotomously scored test (see below). Given that the data are from the same subjects (i.e., correlated), how ...
3
votes
1answer
110 views

Outliers on discrete data

Is there any robust methodology to identify outliers in the discrete data distribution. I am specifically concerned with discrete geometrical distribution? P.S. Data transformation does not seem to ...
1
vote
1answer
25 views

Analyzing/visualizing tightly grouped discrete results

I've been having a very hard time finding a good representation (visual or analytical) for lots of data points on a very small, discrete scale. e.g. given a set of results from 1 to 5 in increments of ...
1
vote
2answers
536 views

Difference between geometric distribution and negative binomial distribution

How do I differentiate between a problem of geometric distribution and that of Negative Binomial Distribution? Both include something around first success or failure. I'm confused.
0
votes
1answer
113 views

Meaningful Sample Size

I have a set of 100 people each assigned to one of the four groups (very short, short, tall, and very tall). How many people's height do I have to measure to know the general distribution of people ...
1
vote
0answers
19 views

How to determine if a dichotomous variable is randomly distributed or is predicted by other instances

I have a product with a measurement of X features. Each feature can either be a PASS or a FAIL. Which statistical test can I use to tell if the failures are randomly distributed across all features? ...
4
votes
1answer
76 views

Multi-dimensional CDF on a discrete support

Suppose I have two discrete-support random variables, $X$ and $Y$. They have joint CDF $F(X,Y)$. If I want to find $\Pr(a \leq X \leq b , c \leq Y \leq d)$. It is obviously not: $F(b ,d)-F(a-1 ,...
1
vote
1answer
86 views

Most powerful test for deciding probability mass function

Let $X$ be an integer valued random variable supported on $\{0.1.2...,12\}$ whose pmf is either $g(x)=1/13; x=0,1,...,12$ or $ f(x)=\dfrac x {36} 1_{\{0,1,...,6\}} + (\dfrac 13 - \dfrac x{36})1_{\{7,...
1
vote
1answer
60 views

Model time series as real-valued or integer-valued?

I have a positive-valued time series of daily prices (a sample is listed below -- there are a few thousand observations) that is recorded to two decimal places. It is stationary after computing the ...
0
votes
0answers
10 views

Censored Dummy Regressor

I have a dataset that contains factors corresponding income ranges of sampled persons, like people with factor 1 earn between 10,000 to 20,000, 2 between 20,000 to 30,000 . I could just make dummies ...
2
votes
1answer
91 views

How to calculate the covariance matrix for a categorized variable?

Let $X$ and $Y$ be jointly distributed as a multivariate normal with the following parameters: $$ \mu_{XY} = \begin{bmatrix} 0 \\ 0.2 \end{bmatrix} \qquad \Sigma_{XY} = \begin{bmatrix} 1 & 0.05 \...
0
votes
0answers
23 views

Is there a method to find optimal discrete options from continuous data?

I have human perceptual data measured in a continuous scale. I am however not sure that the underlying variable being measures is in reality continuous, in fact I believe it might be a discrete scale. ...
0
votes
1answer
51 views

Comparing two discrete independent variables

I would like to perform something like two-sample Wilcoxon tests/T-test (paired = FALSE) to compare two method's expected scores. Here is the table of counts: ...
1
vote
0answers
33 views

Is there a distribution such that a sum of its samples creates the uniform distribution? [duplicate]

Say I sample $N$ numbers from a mystery discrete distribution and add them all together. My goal is for the sum of these random variables to be uniformly distributed from $[a,b]$ and thus the ...
1
vote
0answers
22 views

Prove bi-directional relationship between convergence in distribution and convergence of probability mass functions

Let $X$ be a random variable that is positive and integer-valued. Let $X_1, X_2, ...$ also be random variables that are positive and integer-valued. Prove that $X_n$ converges in distribution to $X$ ...