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).
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45 views
Can all methods made for certain level in measurement hierarchy used at all higher levels?
Let's say there's a measurement hierarchy for discrete variables, that looks like nominal (grade pass/fail) < ordinal (grade A/B/C) < interval (grade 90-100; 80-89; 70-79, etc). Hierarchy is ...
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0answers
45 views
How do I test for significant difference between sets of time ordered data?
I have data about activity on a game site over a period of time (~1.5 years). I want to compare a sub-population's activity between certain time segments so that I can say things like "Group A played ...
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1answer
75 views
Analysis of discrete (count) time-series data
I have a 2X2 factorial experiment where I am interested in seeing the effect of two different nutrient solutions (N and W) on the appearance of root tips of two different plant species (A and B). I ...
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0answers
27 views
Mathematical sound way to rediscretize a distribution
Case:
I have a discrete distribution with a certain interval level. I want to rediscretize it so that the interval level is reduced, but the general characteristics of the distribution remain intact.
...
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0answers
17 views
Distribution analysis of values obtained in repeatable simulations
I have some computer simulation after running which I'm getting a fixed-length vector of results which take values from fixed small set of sequential integers (e.g. {1,2,3,4,5,6,7,8,9,10}). I need to ...
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1answer
67 views
Equivalent to K-S test on discrete data with uneven quantization
I have some data resulting from a simulation that consists of several groups, each containing a single real datapoint and a variable number of matched controls. I take the rank of each real value ...
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0answers
29 views
Comparing divergence from uniform distributions with differing supports (discrete)
Imagine we have a potentially biased coin and a potentially biased six-sided die and we want to know which is more biased than the other.
Firstly, is this a reasonable goal? Could it make sense to ...
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0answers
40 views
Price elasticity of specialized goods
What type of "declared-intention" survey would be adequate to measure the price elasticity (among the general public) of a product, such as a car battery, for which the following applies:
The only ...
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0answers
44 views
Discrete distribution fitting
I have a discrete sample, numebr of passengers. when I try to find the best fit to this data set, none of the discrete distribution give the good fit according to goodness of fitness test. but the ...
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1answer
118 views
Using conjoint analysis for price elasticity
I have been asked to use conjoint analysis to find the price elasticity of a certain category of products. I have never used conjoint analysis before and have been reading about it for a while. I have ...
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1answer
99 views
How to compare similarity between two discrete distributions
I am trying to compare two temporal distributions. To give an example, consider two factories. For each factory we have a distribution of number of hours taken to produce a product. E.g. 40% of total ...
2
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1answer
37 views
Semi-discrete probability distribution
I am somewhat new to statistics, so bear with me.
I have a dataset that contains integer values. I created a model for this dataset such that
y(x) = f(x) + c
...
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1answer
214 views
Kmeans on “symmetric” data
A set is said to be fully-symmetric if for every x in it, negating one of its components results in y such that y is in the set as well.
A set is said to be semi-symmetric if for every x in it, ...
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0answers
24 views
Remove variance from temporal observations (input to HMM emission) by manipulating the individual observations
I have 52 weekly observations of count data that has some spikes and a definite trend (available here).
...
5
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1answer
67 views
Measure of dispersion over unordered set
I'm looking for a measure of dispersion, such as standard deviation, that can be used when distributing to an unordered set.
Specifically: A bucket distribution assigns a non-negative value to each ...
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5answers
183 views
How can I find distribution from mean and variance
If I know the mean and variance of a discrete random variable $\in \{0,1,\dots \}$, How can I find the distribution?
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0answers
159 views
Basic questions about discrete time survival analysis
I am attempting to carry out a discrete time survival analysis using a logistic regression model, and I'm not sure I completely understand the process. I would greatly appreciate assistance with a ...
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2answers
337 views
Kolmogorov-Smirnov with discrete data: What is proper use of dgof::ks.test in R?
Beginner questions:
I want to test whether two discrete data sets come from the same distribution. A Kolmogorov-Smirnov test was suggested to me.
Conover (Practical Nonparametric Statistics, 3d) ...
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0answers
64 views
How many parameters does a HM-SVM require?
How many parameters does a Hidden Markov Support Vector Machine require?
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2answers
138 views
Dependent Bernoulli trials
The probability of a sequence of n independent Bernoulli trials can be easily expressed as
$$p(x_1,...,x_n|p_1,...,p_n)=\prod_{i=1}^np_i^{x_i}(1-p_i)^{1-x_i}$$
but what if the trials are not ...
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0answers
68 views
Discrete time survival analysis with varying length event windows
I have data that appears very well-suited to discrete-time survival analysis, in that each subject has a consecutive sequence of observations from its entry into the system until its exit, and I'm ...
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2answers
241 views
What's the name of this discrete distribution (recursive difference equation) I derived?
I came across this distribution in a computer game and wanted to learn more about its behaviour. It comes from the decision as to whether a certain event should occur after a given number of player ...
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0answers
35 views
How to discretize training and test files to not encounter inconsistency in data?
I have a problem in discretizing my data. My data comprises of two parts: training data and test data. I discretized training data using some parameters of equal-width binning and used the same ...
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1answer
123 views
Marginalizing a conditional distribution
Suppose I have a conditional discrete distribution $P_{M|A}(m,a)$. If I take sum over $m$, i.e. $\sum_{m}P_{M|A}(m,a)$, do I get $f_A(a)$, where $f_A(a)$ is the pmf of the random variable A?
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1answer
140 views
Sampling in discrete distribution
At the moment I'm working with an algorithm that calculates probabilities $Z$ for a finite sequence of data points $X= \left\{ x_1,x_2,...,x_n \right\}$ using an expression like:
$p(Z_i| X_i,\theta) = ...
5
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1answer
186 views
Discrete data & alternatives to PCA
I have a dataset of discrete (ordinal, meristic, and nominal) variables describing morphological wing characters on several closely related species of insects. What I'm looking to do is conduct some ...
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0answers
62 views
What happens when you add a varying term to the thresholds in ordered logistic regression?
Specifically, I would like to know what ologit in STATA estimates because I tried a simulation and I had really weird outputs. So I'd like to know how exactly adding a varying term to each threshold ...
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1answer
33 views
Computing the dyadic add portion of the Walsh-Fourier spectral density
I am attempting to build a Walsh-Fourier spectral density and it appears that it is first required to compute the logical covariance which in turn involves a dyadic add.
I am not at all familiar with ...
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2answers
55 views
perturbing discrete probability distribution
What is the best way to slightly perturb a given discrete probability distribution ?
Adding a zero mean Gaussian noise to the probability distribution and re-normalizing it such that it sums to 1 is ...
7
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1answer
120 views
Distributions on subsets of $\{1, 2, …, J\}$?
I'm wondering if there are any sorts of standard distributions on subsets of integers $\{1, 2, ..., J\}$. Equivalently, we could express this as a distribution on a $J$ length vector of binary ...
7
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1answer
112 views
Conservativeness of Tests Based on Discrete Random Variables
For discrete test statistics, the distribution of the corresponding $p$-value is discrete and stochastically larger than the uniform distribution. Hence the corresponding hypothesis test based on the ...
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1answer
85 views
Rebalancing discrete probability distribution
I'm working on a machine learning algorithm and have gotten stuck with how to rebalance a discrete probability distribution. I have a distribution represented as a simple array of $n$ numbers which ...
6
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1answer
135 views
Likelihood test for dividing a distribution into two separate distributions
I've been google-ing around but couldn't find an answer to my question. Any help would be appreciated.
The simplest example of my problem is: Imagine I have an bag of marbles of many different ...
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1answer
33 views
Sampling subsegments from discrete input ranges
I have an set of input ranges {[a1, b1], [a2, b2], ...}. Each a and b represent integer ...
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2answers
236 views
Robust fitting of discrete choice model in R
I'd be really grateful for recommendations of a robust package for fitting discrete choice models to a large amount ($n$ in the millions and $p$ in 2000 range) of data. I want a smoothed model that ...
6
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1answer
116 views
What are Effective Regression Techniques for Linguistic Analysis of Linked Data?
Cross-post from MathOverflow where it was suggested that I might get better results here.
I am in the early stages of a problem that involves parsing a large number ($\approx 5 \times 10^9$) of ...
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0answers
56 views
How to define and model consumption bundles?
Imagine an a la carte buffet with n different rooms. On entering the buffet you pick a room (let's say American, Mexican or Italian food) where you stay for the duration of your visit.
Once in a ...
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0answers
72 views
Distribution from which to sample integers evenly between 1 and 1000? [duplicate]
Possible Duplicate:
Are there default functions for discrete uniform distributions in R?
Is there a distribution from which I can sample that can act as a relatively flat prior over a given ...
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0answers
123 views
Is there any way to fit an exponential model with a discrete predictor in R?
I'm trying to estimate the growth rates of a number of ant colonies. I have measured colony mass at three different time points. I was thinking about measuring growth rate by fitting an exponential ...
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1answer
109 views
What is the state-of-the-art regarding sampling from discrete distribution?
After struggling with auto-Poisson model (a.k.a. Random Markov Network with conditional Poisson distributions) trying to force Gibbs sampler to obtain discrete sample of the network (since I know ...
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0answers
179 views
What PDF should be fit to a rank histogram?
A Rank Histogram (or Talagrand Diagram) is a neat way of measuring whether your numerical model is giving appropriate variance. It's used for weather and climate forcasting, where you only have one ...
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0answers
115 views
Calculating $R^2$ when one variable can only take integer values
I am a programmer, not a statistician, so pardon my botched use of the terms. My basic problem is this: I am wanting to calculate $R^2$ between a known concentration (which can be any non-negative ...
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0answers
64 views
Determining significance of multiple nominal predictors on discrete response
What type of statistical tests should I look into for determining which of several nominal predictor variables have the largest effect on a discrete/ordinal response variable?
Say that the five ...
4
votes
2answers
111 views
How to be sure about the distribution of a discrete and limited stochastic variable?
I've got a stochastic variable $X$ which takes the values in $\{0,1,2\}$ with some unknown probabilities. I want to know the distribution, and can sample $X$ as many times as I want to. How many times ...
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0answers
437 views
How best to normalize count data to compare two distributions
Say I have a vector of length 1000. At each position (1 ... 1000) there is a count. I have two vectors with different range of counts such that in vector A the maximum number of counts at a position ...
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1answer
315 views
Is there a fuzzy distinction between discrete and categorical variables?
Are there some variables where it can be difficult to assess whether they are purely categorical?
For example:
To assess the level of pain that a patient is in, you use a scale between 1 and 10.I ...
4
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2answers
103 views
Classifying integer sequences by their first difference
I don't know exactly how to describe what I'm looking for, but I will try to make some examples. Let's take three different data series:
Series A: 1,2,3,4,5,6,7,8,9,10,9,8,7,6,5,4,3,2,1
Series B: ...
4
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3answers
763 views
Clustering a dataset with both discrete and continuous variables
I have a dataset X which has 10 dimensions, 4 of which are discrete values.
In fact, those 4 discrete variables are ordinal, i.e. a higher value implies a higher/better semantic.
2 of these discrete ...
5
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1answer
142 views
Expected value for discrete (nominal) variable?
I'm trying to understand the concept of the expected value.
Especially, what bothers me is the expected value for discrete random variables. I will try to formulate it by examples:
The expected ...
3
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1answer
538 views
How to fit Bradley–Terry–Luce model in R, without complicated formula?
The Bradley–Terry–Luce(BTL) model states that $p_{ji} = logit^{-1}(\delta_j - \delta_i)$, where $p_{ij}$ is the probability that object $j$ is judged to be "better", heavier, etc, than object $i$, ...
