A random variable $X$ is called continuous if its set of possible values is uncountable, and the chance that it takes any particular value is zero ($\text{P}(X = x) = 0$ for every real number $x$). A random variable is continuous if and only if its cumulative probability distribution function is a ...

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18 views

Why Binning Variables in Predictive Analytics?

Lot of discussion in CrossValidated focuses on optimal binning methods, binning example etc. But I am trying to figure out what are the scenarios that I have to bin variables whereas it's better idea ...
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2answers
46 views

Large differences between raw (plotted) data and least-squares means from mixed model

I’m analysing data with mixed-models (using the afex package which I believe is based on lme4) from an experiment that had a ...
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1answer
34 views

Marginal Probability Density Function of Joint Distribution

I have this question regarding marginal probability density function of joint distribution. Following is the equation I have. $$f(x,y) = \begin{cases} \frac{3}{2} y^2 & 0 \le x \le 2 \text{ and } ...
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1answer
67 views

Correct glmer distribution family and link for a continuous zero-inflated data set

Data set details: Zeros are "real" (volume) Data set is heavily left skewed (even when zeros are excluded) Response is continuous (volume) Can anyone recommend a distribution family and link that I ...
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1answer
30 views

Regression models in temperature data

I am quite new to the whole modelling world so I ask your understanding. Can glm models be used for modelling continuous variables? I ask this because I have read that glms are most commonly used to ...
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26 views

Normality check for continuous data

The results of my normality check using Skewness and Kurtosis do not seem to be in support of normal data (my data has 1272 observations). Even after winsorising the variables (bottom 5% and top ...
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1answer
22 views

Can I perform a chi-squared analysis with a categorical variable and the means of a continuous variable?

I have one variable that is categorical (with 5 levels), and another variable that consists of either mean or sum scores (0 to 28) due to the way you have to calculate the scores of this measure. Can ...
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0answers
26 views

How best to identify candidate error-prone independent variables

I am working on some blood flow data, obtained through doppler. The resulting dataset is a time series, in which each row consists of the following variables: timestamp vessel cross sectional area ...
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1answer
91 views

Odds ratio of a continuous variable (univariate cox proportional hazards), how to plot that variable against death%?

I have a continuous variable X with which i ran Cox proportional hazards. The outcome was 1=Death, 0=censored/still alive. I have an odds ratio 0.516 for this predictor. 1) How do i interpret that ...
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1answer
24 views

Continuous vs. categorical variables in interaction terms

My analysis includes, among others, three independent variables: X (interest rate), Y (type of rate; it is a dummy), and Z (likelihood of bankruptcy). I have transformed the latter into a categorical ...
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0answers
51 views

Banding variables for initial GLM fit, then replacing with continuous versions. Any pitfalls?

I am aware of some of the pitfalls of using banded versions of continuous variables when fitting a GLM (or other model), with a number of discussions on the subject on this forum (and a excellent list ...
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3answers
186 views

Conditional probability of continuous variable

Suppose that random variable $U$ follows a continuous Uniform distribution with parameters 0 and 10 (i.e. $U \sim \rm{U}(0,10)$ ) Now let's denote A the event that $U$ = 5 and B the event that ...
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18 views

Combining two data sets with different weightings, possibly Bayesian Updating?

I am a PhD student and I am currently looking at railway track degradation. As part of this I am finding linear fits of the track geometry recordings against time to give a degradation rate. The ...
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1answer
26 views

Sample size calculation for the comparison of the means of three groups

I have to calculate the sample size for my project. The study is a comparison between three different treatments at three different time points. The outcome variable takes continuous values. We ...
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1answer
27 views

How to estimate rating of a customer?

I have data about customers transactions contains: ratings of customer $r_{ci}$ to service $s_m$ which has quality $q_m$. Quality is assumed to be a real value from [0, 1]. Rating is discrete values ...
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1answer
65 views

Significance of continuous variables

I have a table with several numerical continuous measurements and an indicator column catastrophy ...
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2answers
45 views

Does clustering need scalar data?

I am trying to cluster 43,000 individuals on about 50 variables. The data contained in the variables are minutes of a radio shows which people listened to in the range of 0 - 3,000,000 minutes. My ...
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0answers
29 views

To BIN or not to BIN a continuous data to get a Fragment Size Distribution ?

I have a data set in excel of almost 6000 entries (quantitative and continuous => P(X=x)=0, I mean the possible values for my continuous random variable X are uncountably many). Each point will ...
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1answer
24 views

Continuous predictor of a significant difference on another scale at T1 and T2

I was wondering if anybody could point me in the right direction for a statistical test. I’m looking whether a continous variable (e.g. a personality variable) predicts a significant difference ...
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1answer
57 views

Measure of association between non-dichotomous ordinal variable and continuous variable

I have to collect and then analyse a large dataset. A particular data input (continuous variable) is laborious to collect and I believe that an ordinal category (1,2,3,4) would correlate closely with ...
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1answer
304 views

Why is this random variable both continuous and discrete?

The waiting time, $W$, of a traveler queuing at a taxi rank is distributed according to the cumulative distribution function, $G(w)$, defined by: $$G(w) = \begin{cases} 0 & \text{ for } ...
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1answer
59 views

Analyzing relationships between ordinal and continuous time series data

I have two sets of time series data - roleTrajectories & normalizedDegree. The former data set contains ordinal rankings of subjects' positions within a network at 13 time periods. The latter data ...
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0answers
17 views

continuous norming

I am said to apply continious norming to my data (test scores testing children). I have not found any freely available information about this process. I have found out that: 1) norming is based on ...
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1answer
67 views

Bayesian linear regression with continuous and binary covariates

I am interested in learning more about applying Bayesian linear models for covariates some of which are continuous and some are binary. What is the appropriate terminology for such models so that I ...
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0answers
27 views

Testing for a 3-way interaction between a within-subjects factor, a continuous IV and a categorical IV in SPSS

I'd like to test whether the moderating effect of a (continuous) personality variable on the effect of an experimental manipulation differs between conditions. Does anyone know how to go about this in ...
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0answers
23 views

split plot with continuous sub-plot factor?

Question in a nutshell: In a split-plot design, can factor B, the treatment applied to the subplot, be a continuous variable, and can there only be one block?(I read that blocks in split-plot designs ...
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27 views

Predicting continuous response with a mix of categorical and continuous variables

What regression method should I use to construct a model predicting a continuous response with a mix of categorical and continuous variables? I would do this with SPSS (16.0) and was thinking of using ...
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3answers
364 views

Uniform random variable as sum of two random variables

Taken from Grimmet and Stirzaker: Show that it cannot be the case that $U=X+Y$ where $U$ is uniformly distributed on [0,1] and $X$ and $Y$ are independent and identically distributed. You should not ...
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0answers
46 views

Appropriate classification model for combination of continuous, binary and categorical inputs

I have a binary classification problem for classify my samples to two classes (class_1 and class_2). I have different kinds of ...
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0answers
15 views

R [nlme] Incrementing / Adding units to continuous covariates?

I'm trying to find out how I can change the beta estimates for a continuous covariate in my model from 1-increment to another increment. For example, if I have age in the model, and I want to ...
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23 views

Methods for predictive modeling on continous target

I am trying to put a continuous target into predictive modelling method. The target is an amount that can range from 0 to unknown. I have roughly 1000 records (for modelling and validation ...
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1answer
233 views

How to transform continuous data with extreme bimodal distribution

Is there a way to transform a continuous predictor variable (grant) that has a bimodal distribution into a normal distribution (see density plot below)? I have tried log(x+c), z-score and inverse ...
2
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1answer
38 views

What is a continuous variable in statistics?

Continuous variables can be split into three categories according to statements over here: http://www.unesco.org/webworld/idams/advguide/Chapt1_3.htm. One category is Interval - scale Variables. It ...
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17 views

Fitting a logistic regression model with continuous variables without a constant mean

I'm trying to incorporate a continuous variable to a logistic regression with regularization model I've already tested with only binary variables. I know that, if I'm using regularization, I must ...
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1answer
97 views

Is there an R package to calculate differential entropy

I am trying to calculate differential entropy over my data. This is how a subset of my data set looks like : ...
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28 views

Estimating a probability distribution with a discrete and continuous part

This is a question more for advice and a suggested starting point than anything else (though anything else is cool as well ) The data that I have is something like this - 1,000,000 data points of ...
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153 views

Normal Distribution with mean and standard deviation

I'm trying to solve the following problem: Suppose at breast height, the diameter of trees of a particular type is normally distributed with mean=8.8 inches and standard deviation= 2.8 inches.What ...
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2answers
216 views

Can C4.5 handle continuous attributes?

I'm trying to play with the breast cancer data available through UCI: https://archive.ics.uci.edu/ml/machine-learning-databases/breast-cancer-wisconsin/wdbc.data When trying to classify the data ...
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2answers
225 views

When can a continuous variable be treated as categorical?

I have a continuous variable, which can take any value between 0 and some large, though not infinite, number. Let us assume that the maximum possible value is 1000. The values are nowhere near ...
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1answer
748 views

Correlation between a nominal (IV) and a continuous (DV) variable

I have a nominal variable (different topics of conversation, coded as topic0=0 etc) and a number of scale variables (DV) such as the length of a conversation. How can I derive correlations between ...
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0answers
47 views

Absolutely continuous probability distribution and its probability density

A Wikipedia article states: A random variable $X$ has density $f_X$, where $f_X$ is a non-negative Lebesgue-integrable function... $F_X$ is the cumulative distribution function of $X$... ...
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2answers
99 views

Time series - plotting continuous and categorical variable

I have one dependent continuous variable and an independent categorical variable. Each one minute window on a time series is marked with one category, for example 10:00 - 4, 10:01 - 1, 10:02 - 5, ...
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64 views

Controlling for categorical variables before correlation using residuals?

I’m looking for a way to control for the effect of multiple categorical variables, all of which contain two independent categories, on two continuous variables before I correlate these continuous ...
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0answers
8 views

Selecting optimal model when only smoothed data available?

I have a graph of some (highly nonlinear) experimental spectrum which is obtained by smoothing results of several repeated measurements obtained by different experimental methods. The graph also ...
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2answers
58 views

HR of a continuous variable and manipulation of its interval

I am a medical intern trying to understand Cox regression modelling using R. I am using the pbc data of the survival package with the following code: ...
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2answers
115 views

Graph with 2 interacted continuous predictor vatiable

When using glm(link=logit), I detected a significant interaction between two continuous predictor variables. How can I present the results visually using R?
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1answer
242 views

lme() with several within and between (categorical and continuous) subject factors

I am currently trying to analyse data from an experiment of mine and I have done some searching for instructions on the usage of the lme() function for R, since I am looking to analyse my data with a ...
2
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1answer
33 views

What is the “scale” parameter in “continuous autoregressive model” in cts package?

I am trying to use the "car" command in "cts package" in R program and I see the "scale" parameter there. I wonder whether this can be assumed to be equivalent to time intervals for time series ...
3
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1answer
104 views

Can I use Kolmogorov–Smirnov test on my Data?

I am not good in statistics so I desperately need your help. So I have this dataset of distributions, and I want to know if I can use the KS-test on it. the Idea is saying that the feature's ...
1
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2answers
141 views

Combining categorical and continuous variables to calculate a factor

I have a categorical predictor (income) and three continuous predictors (area, no. of bed rooms and no of cars). How can I form a single factor from these variables? In other words I want to combine ...