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A measure of the degree of linear association among a pair of variables.

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Analysis of Multiple Count Dependent Variable and Multiple Binary Independent Variable

I am wondering if Point Biserial Correlation is applicable for multiple binary independent variables and a dependent count variable. I have read how it was derive for a two variable system of one ...
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1answer
18 views

Statistical method to show a cycling pattern

let's say I have multiple time-series $A_i(x)$ and $B_i(x)$. Here, $i$ stands for a person (person 1, person 2, person 3, ..., person $i$, ..). Is there a method to show that the fluctuations in $A$ ...
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8 views

How do i compare two related time series data sets?

Generally I have two time series data sets that are potentially physically related. The data sets are in the form of xy pairs of time and pressure. Generally the pressure will go down but will have ...
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2answers
19 views

How to interpret multiple regression coefficients [duplicate]

I'm running multiple linear regression with 6 variables. For one of the variables D, the correlation coefficient between D and the response Y is - 0.34. But in the regression output, the coefficient ...
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0answers
14 views

Multicollinearity in Linear Mixed Models

I am currently working with longitudinal data and want to use linear mixed models (LMM). As always in regression models, correlations between explanatory variables cause estimation problems of model ...
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2answers
26 views

Correlation between two binary data sets

I am unsure how to do this properly. I have two binary data sets, i.e. values in each data set is either 1 or 0. I now wish to see if they are in any way correlated. I could use Pearson's, but I don't ...
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0answers
13 views

silhouette function in R gives error `NA/NaN/Inf in foreign function call (arg 1)` [on hold]

I am trying to produce silhouette scores of a kmeans clustering with correlation distance in R. I did a k-means clustering using the Kmeans function from the ...
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0answers
7 views

Are the changing of correlations between features and target variables over time a big reason for the failure of predictive models?

Would love to know your thoughts on what I believe could be an important issue in predictive modelling! At the moment I'm really interesting and curious about what makes a predictive model fail. In ...
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1answer
31 views

Calculate the implied correlation for missing cells in a correlation matrix in R

I have a correlation matrix in R. Many of the correlations are specified, but there are some that are "NA". eg, A __ B __ C A 100% NA 25% B NA 100% 50% C 25% 50% ...
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0answers
6 views

Remove correlated variables using SPSS [on hold]

This is a basic question . I use 19 bioclim variables, asc raster files. I want to remove correlated variables using SPSS. I have not used SPSS previously. But have some resources that i can follow. ...
2
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1answer
63 views

Keep eliminating data points until good correlation coefficient is obtained-using Python

I have been trying to find out a way in order to eliminate outliers from a dataset. The outliers are removed the following way: Any value which results into a 10% reduction in R2 value needs to be ...
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1answer
19 views

Which test to compare Vitamin D serum level between malignant and benign tissues

I have Vitamin D levels for both malignant and benign tumor types and I need to compare them. Which test should I use, unpaired t test ? Another question; I have also PSA level ( also continuous data ...
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5 views

univariate linear regression tests for feature selection?

I have been reading about the f_regression function that is available under the package feature_selection of scikit. According to what I read and I cite it says: Linear model for testing the ...
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1answer
38 views

Simulating data based on correlation coefficient? [duplicate]

If a numerical vector $\vec{x}$ is a sample drawn from a normal distribution, given a correlation coefficient $\rho$ is there a way to simulate a second vector $\vec{y}$ such that the $corr(\vec{x},\...
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0answers
11 views

Correlation between two Z variables [closed]

I have two XYZ datasets, with the same XY variables, but with different Z variable. How can I calculate the correlation between the Z variables in the datasets? Thanks in advance
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1answer
64 views

Which technique for this regression problem?

Here's a sample problem I'm trying to solve and I would love your advice: You run an ice cream store. You sell n different flavors of ice cream You want to drive people towards buying a ...
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0answers
15 views

Remove highly correlated variables before regression - partial or pairwise correlation?

I am using vegan's bioenv() function to find the best (sub)set of variables in one distance matrix (env parameters) that explain the structure of another distance matrix (species abundance). Several ...
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1answer
40 views

Correlation between two quantitative variables

I have two quantitative variables, one with negative and positive values (let's call it A), and the other with solely positive values (let's call it B). I would want to do the correlation between ...
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0answers
95 views

Causal estimates have high correlation with naive estimates - what may this imply?

In an observational study, suppose that individuals can choose from $N$ different treatments, and there are the same confounders for each treatment and the outcome. The naive probability, $\frac{\text{...
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19 views

Why is distance covariance defined squared, while covariance is not?

I am dealing in a data science project with correlation analyses using pearson and distance correlation. While trying to understand the differences between them, I learned about the differences by ...
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1answer
37 views

How can centering predictor variables reduce correlation between them?

In Statistical Rethinking by Richard McElreath on pg. 320 he states “centering predictors can aid in inference, by reducing correlations among parameters”. For a linear equation with an interaction ...
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3answers
1k views

How is it possible to obtain a good linear regression model when there is no substantial correlation between the output and the predictors?

I have trained a linear regression model, using a set of variables/features. And the model has a good performance. However, I have realized that there is no variable with a good correlation with the ...
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4answers
272 views

Sufficient and necessary conditions for zero eigenvalue of a correlation matrix

Given $n$ random variable $X_i$, with probability distribution $P(X_1,\ldots,X_n)$, the correlation matrix $C_{ij}=E[X_i X_j]-E[X_i]E[X_j]$ is positive semi-definite, i.e. its eigenvalues are positive ...
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0answers
57 views

Correlation between X and max(X,Y)

If I select a random value X from density f, and Y from density g, is it possible to estimate the correlation between X and max(X,Y)? The limits are obvious: if $P(X<Y) = 1$ then $\rho = \rho_{xy}$...
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0answers
11 views

Partial dependence plots and high correlation between variables

I was wondering if it's OK to use partial dependence plots when some of the variables are highly correlated. Is it OK to interpret the results as always?
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2answers
480 views

Is Spearman correlation never greater than Pearson correlation?

If Spearman correlation is Pearson correlation, but on ranks of the data - does it mean that absolute Spearman will always be lower or equal to absolute Pearson correlation, but never greater? Is it ...
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0answers
16 views

Correlation coefficient on binary variables

I have two binary variables and want to test their association. From what I've read I need to use the chi-squared ($χ^2$) test. The measure of their association is then described through the Phi ...
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0answers
8 views

Is it suitable to test correlation between 2 variables using data by hour of day and day of week (ie. 148 pairs of data)? Is there a special approach?

Typically when conducting correlation analysis I have had time series data with day or week of the year, however my current data set has hour of day per day of the week for 7 days. I want to test the ...
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1answer
8 views

Gpower: Correlational power analysis

I would like to perform a power analysis on Gpower. The only bit of information that I have is provided in the image below: This is what I have done so far: Am I doing it right ? Thank you
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0answers
27 views

Correlation coefficient $(Y=aX+b)$

Consider two random variables $X$ and $Y$. Assume now that $Y=aX+b$ where $a<0$ and $-\infty<b<\infty$. Determine the value of the correlation coefficient $\rho(X,Y)$. My attempt. $$\rho(X,...
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1answer
39 views

Are Linear Regression associations correct with a binary dependent variable?

Probably the simplest model when dealing with a binary classification problem is logistic regression. This relies on fitting a linear regression model to the data and then applying a sigmoid function ...
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1answer
15 views

Kendal's tau correlation if only one variable is ordinal

I have a vector with 3000 data points consisting of values on a likert scale from 1 to 9. It is ordinal data without normal distribution. Now I would like to calculate the correlation of this vector ...
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1answer
26 views

What test should I use? Spearman correlation?

I want to understand if a classroom's quality score differs for classrooms with varying percentages of special ed students. Percentage of special ed students is a categorical variable, grouped into ...
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0answers
13 views

Comparing sample correlation coefficient with population correlation coefficient

Assume there is a population, P, of size N. Each member of the population has three variables associated with it, a nominal variable C (with m unique categories), and two continuous variables X and Y....
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1answer
28 views

What is the difference between CCA and ordinary correlation analysis?

Ordinary correlation between two multidimensional variables would give similarity between these variables, whereas canonical correlation analysis (CCA) would find two linear transforms to obtain ...
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0answers
7 views

How to estimate a histogram for two correlated input parameters when the resulting histogram is known?

Let's assume there are two (slightly correlated) parameters (A and B). Both parameters are rated with discrete values (range: 1-5). The sum of the two parameter-ratings gives the cumulative-rating (A+...
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0answers
18 views

What is the difference between multicollinearity and correlation?

I have a set of data and I wish to construct a multivariate regression model for predicting. I saw that if the variables are multi-colinear the multivariate regression model will be bad. I don't know ...
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0answers
6 views

How to test association between rank difference and continuous numerical variable

Suppose we have two timepoints, $t_1$ and $t_2$, and a population of size N for which, at each time point, we have rankings of the members of the population, $x_1$, $x_2$,...$x_N$, and also observe a ...
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0answers
22 views

Testing the significance between two correlations in Python.

I've seen some similar articles using R but I'm not sure how to implement this test in python. Suppose I have two datasets, A and B (both contain 35 datapoints), and they predict some time series of ...
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2answers
45 views

Measure correlation for distance and binary outcome

I know enough about statistics to know that I don't know enough about statistics. This is therefore a humble question, and apologies in advance for asking a question that is likely to be missing key ...
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1answer
31 views

Checking for multicollinearity in selection of variables for regression model

For the selection of variables for a regression model, I did a pairwise correlation matrix between the different predictors and the response variable. From the pairwise correlation matrix, I realise ...
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3answers
48 views

R2CV increases over R2

I have a dataset: X Y 4706 77983 7217 48187 5314 1098 10725 91683 10725 27366 And want to show that there is no correlation. ...
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0answers
12 views

Convergence in probability of a multinomial sample correlation coefficient

This problem is from a Ph.D Qualifying Exam on mathematical statistics(also related to probability theory). Let $(X_1,\cdots,X_k)$ be a random vector with multinomial distribution of $n$ trials and ...
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0answers
31 views

cor function between values “1” and “1” in matrix outputs not a value of ''1''

I am correlating values between two matrices (you can find them here) using function WM_x_ACC <- cor(WhiteMatter, Cingulum_Ant_R_Mid_R) However, the ...
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0answers
6 views

Customer satisfaction drivers analysis and Pearson correlation

For a customer satisfaction drivers analysis from survey data, I would like to measure the link between satisfaction of specific attributes (ex. reactivity of service) and overall satisfaction ...
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0answers
12 views

Best correlation statistic between volatile line graphs created from moving average?

I am new to the world of statistics, and would appreciate some help with this basic question: I am plotting line graphs of moving-averages, and there is a pretty clear correlation with the blue and ...
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1answer
22 views

can correlation coefficient be considered a modeling tool?

I have the idea that the objective of a model is to summarize a data set in some numbers that can explain the whole. For example a regression line returns numbers that describe possible relations of ...
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0answers
12 views

Correlation/Grouping of binary matrices

I'm a little bit new in statistical analysis of data, I have some data which looks like this: In the columns, I have different microbes and in the rows different cell types. Each cell in the matrices ...
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0answers
10 views

partial correlation between continuous, binary and ordinal variables

I have a large number of continuous, binary and ordinal variables and am trying to calculate partial correlations between these quantities controlling for age and sex. I am calculating pairwise ...
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1answer
23 views

Coorelation among the independent variables in logistic regression?

I am having a hard time to understand whether the independent variables in a logistic regression have to have some degrees of correlation. I came across a report that mentioned that in SEM the IVs are ...