Questions tagged [r]

Use this tag for any *on-topic* question that (a) involves `R` either as a critical part of the question or expected answer, & (b) is not *just* about how to use `R`.

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3 views

Understanding how fastLink works

First of all, sorry for my English, I'm translating it with google translator. I don't really understand how cut.p.num works. From the manual: ...
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Unable to install the “twosamplemr” package [closed]

I was hoping someone could point out how to resolve this problem: I first entered the following: devtools::install_github("MRCIEU/TwoSampleMR") Then lots ...
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GAM not actually using categorical variables?

I am very new to GAMs, but I am trying to use gam() from the mgcv package to fit a logistic regression model using cubic splines....
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10 views

Fitting GARCH model with external regressors in R

I am trying to fit a GARCH model with external regressors. My goal is to see if the Covid-19 new cases and deaths have an effect on the volatility of daily stock returns. For this I used the ...
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Why are the adjusted P values using the Benjamini-Hochberg procedure in dunn.test and p.adjust different?

After a Kruskal-Wallis test, I wanted to do a posthoc Dunn's test with the Benjamini-Hochberg correction, which I did with the R package dunn.test. I noticed an adjusted P-value being higher than 0.05 ...
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Test score Variable interpretation in Brandsma data (mice package)

I am currently working with the Brandsma data of the mice package in R for teaching purposes. The dataset is from Snijders&Bosker(2012), or rather Brandsma&Knuver(1989) and Knuver&Brandsma(...
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mgcv and cyclic smoothers, am I doing it right?

TLDR: Need advice on implementation of model, particularly cyclical smoothers I'm constructing a model that has around 3 months of daily data (a few days missing) for a response variable that falls ...
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Testing changes in regression predictors between timepoints (independent data) - regression/ANCOVA or mixed model

I have a fairly complex regression model with 14 predictors. I've collected data over five sequential (but not evenly spaced) timepoints, and I want to see whether the importance/direction of the ...
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What does “Model has aliased term(s); df ambgiuous” mean in R?

I'm trying to run crPlots and I keep getting this error crPlots(lm_lifexp) Error in df.terms.default(model, var) : Model has aliased term(s); df ambiguous. How can I solve this?
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How to calculate the effect size for the interaction term (time*Group) in a linear regression?

I need to calculate the effect size for the interaction term (time*odours) of this below linear regression. I can't use Cohen's $f^2$, as is commonly presented in a ...
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Interpreting the covariate p-values in a multivariate generalized linear model

If a covariate in a GLM is "significant" does that mean it is significantly different from the base case (the group not shown)? Say we have three groups, Control, Exp1, Exp2. We are ...
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How to interpret the random effect of a random slope model?

I designed an experiment to observe the shading effect in the distribution of 2 species of crabs through time. So basically I have 4 levels of shading (no shade, 20%, 50%, and 80%) with 7 ID to each (...
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What model is appropriate for flow cytometry data with dependent variable as a percentage?

I have some flow cytometry data where my dependent variable is measured as a percentage (number of cells expressing marker/total number of cells measured in that sample). My independent variables are ...
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Pre-/Post Design controlling for pre-differences, clustering and survey weights with lmer

I'm only getting started to use R for a research project about multimorbidity in old age. Multimorbidity was measured twice at an interval of 5 years (t1, t2) in 840 participants. There was no ...
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Theta (thetaEst) estimates in CatR with known item parameters - assessing a whole dataset

To my R angels, After a recent voyage of discovery, I have been using IRT to develop a set of GRM derived item parameters on a large dataset of 40000 questionnaire responses. I would like to use these ...
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Is this Fitted vs Observed diagnostic plot strange?

I am running a linear regression model in R with generalized least squares gls() on my data to fix residuals with unequal variance. I seem to have achieved this; ...
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What's the Statistical test to use to compare the means of two correlated time series (i.e., t-test for time series)?

I hope everyone is doing well. I have a question about the statistical methods of comparing two time series. I got monthly data from 1/1/2019 – 1/10/19 (10 observations). I would like to compare it to ...
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Why are variables in GLM being split into multiple output variables

I have input for glm that looks like BMI $grp PRS age gene 24.2 1 3.0 77 0.0 33.8 1 4.0 89 0.0 30.3 1 7.0 58 0.0 I’m inputting this into ...
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How to calculate CDF in R? [closed]

How to calculate CDF in R? I need to calculate the cumulative distribution function of a data sample. Is there founction to calculate value of cumulative density function in R ?
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How to do compare levels (multiple comparisons) of a factor variable when the model includes an interaction term in linear mixed models?

Hopefully, my title is not too confusing. I have two scenarios (ajo) completed after another (scen 1, scen2). A number of participants completed two scenarios in groups of four people. Each group ...
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Recovering factor level estimates from contrast estimates

Using R I have fit some data to a model of the form y~A*B where A is a factor with levels A1, A2, ..., A5 and similarly with B. I am using a different contrast than the default, so the results do not ...
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1answer
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Predictions from hurdle models in R

I am using hurdle models to predict a continuous cost variable that has many exact zeros. I have fitted a hurdle model with a binomial component and a gamma component, but when I am trying to combine ...
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8 views

Feature Engineering and prediction with R and python [closed]

I have a sequential dataset, and have 2000 rows for 300 ID. I have 20 variables (i.e in my real dataset) ...
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Accounting for unequal sample sizes - offset() code and which data to use

I have a set of data that contain two separate species placed in 4 habitat types. One of the species has 10 less organisms than the other for a particular habitat and I was hoping to account for the ...
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1answer
16 views

Random walk variance in R less than expected

I am trying to prove via some Monte Carlo simulation that the variance of a random walk equals $t*σ^2$ in R. I am running the following code, 180 times, to find the variance of 180 different random ...
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1answer
29 views

Why are my predictied values from a Bayesian AR(1) model lagging behind the data?

Summary: I have simulated some data on an AR(1) process in R and fit the model in Stan. When plotting the predictions, the predicted values tend to lag behind the true values. Why is this? Detail I am ...
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experimental design in R project

I want to know of any repositories that contain complete experimental design in R covering basic tests and analyses? I want to take a top-bottom approach to learn step by step through a real project ...
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1answer
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R - How to the new data set (Y) from principal component analysis (PX =Y) [closed]

I have done all my principal component analysis and have my principal components (PC1 & PC2) and I know I have to multiply that by my original data set to get my new reduced data set, but I keep ...
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5 views

Adding text to a boxplot that does not have a numbered axes [migrated]

I am interested in labeling my boxplot with the letter A in the top left corner, but because I have a categorical X axis comparing season (summer vs winter), I am unable to give coordinates for my ...
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Plot multiple imputation results from mitml [closed]

I have pooled results from the mitml package: ...
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11 views

Calculating expired vouchers, given a fixed window

Problem: I have time series data for vouchers being earned and redeemed. Vouchers only last for a 3 day fixed window including the day they were earnt eg. a voucher earnt on 1st Jan would be active ...
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10 views

Comparing reduction rate between groups

I was wondering whether someone could help me to solve a statistical issue. I observed that by increasing an independent variable (task complexity), a dependent variable (score) decreases considering ...
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9 views

doing a cross validation mean squared error on a time series data using fable's prophet

I'm trying to do a time series cross validation with the fable prophet model on an increasing window for training and a h = 1 lag for estimation. Here's my code ...
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Seasonal time series data [closed]

I am trying to analyze data that was collected over a few decades. I have monthly data points from August through May (with a lot of data gaps and some months with multiple data collected), but ...
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23 views

How do I interpret a simple linear regression model when both dependent and independent variables are square root transformed? [duplicate]

Overview I built a simple linear regression model to understand if Universal Healthcare Index predicts suicides. My independent variable is Universal Healthcare Index (scale from 1 to 100). The ...
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1answer
29 views

How to interpret lm output [duplicate]

I've run the lm code below, with one DV and three IVs, and I'm not sure how to interpret the output. What does (Intercept) refer to, and what is that row telling me? What are the other rows telling ...
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7 views

How would I conduct an equivalence test in R from an lmer() model?

Lets say I have a null result, as in the following example: library(lme4) iris$Rand <- rnorm(150) m <- lmer(Petal.Width ~ Rand + (1|Species), data = iris) ...
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5 views

R Library for Ordinal Regression with Split-Plot (Cluster?, Repeated Measures?) Structure

I have a data set with the following structure. The response is ordinal. There is an experimental factor (with two treatment levels, each treatment level applied to a different sample of subjects). ...
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9 views

Diagnostics of a parametric Survival Regression in R

I am doing a Survival Analysis in R with the "survival" package and I don't know how to do any plots of the results for diagnostic purposes. Here is my model (I have given the variables self-...
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17 views

How to specify that I have both independent and repeated measures predictor variables in my glmer model?

I am having a little bit of trouble wrapping my head around how to specify my glmer model. My design is as follows: y is a binomial (Bernoulli) response variable x1 is a categorical (factor) ...
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6 views

Test for nonlinearity in cross-sectional time series data in R

I have a cross sectional time series dataset that looks like this: ...
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8 views

Characteristic-Based Clustering of Time Series

I'm trying to teach myself how to apply clustering algorithms to time-series data. I've recently come across a paper (https://robjhyndman.com/papers/wang.pdf) about using time series characteristics ...
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1answer
27 views

Beta regression fitted values

I have a beta regression model in R, have generated predicted (fitted) values based on my data, and plotted lines of those fitted values on a scatter plot of the actual data. I'm most used to GLMMs, ...
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1answer
26 views

Including a weighting variable in a linear regression

I'm looking at how temperature affects length. My length variable is the mean length calculated for every year, it is derived from ~10,000 data points. Not every year had the same sampling effort (e.g....
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1answer
17 views

Moving average (running mean) - how to keep all observations in smoothed time-series?

Let's suppose I have a time-series of 100 daily values and I want to compute a 5-day moving average of this time series. I would do as follows: ...
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1answer
44 views

Dealing with quasi-complete separation in General Additive Model?

I am modelling influence of fire on occurrence of certain bird species (count response variable) in Before/after control/impact experiment design. I've got intact and burned sites and count data both ...
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1answer
29 views

Combine Two Numbers that Satisfies these Five(5) Conditions with R

I want two(2) numbers $\phi_{1}, \quad \phi_{2}$ such that the following five(5) conditions will be satisfied using R: $ \phi_{1} + \phi_{2} < 1 $ $ \phi_{1} - \...
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Question on lagging environmental variables

I am trying to test environmental variables against fish catch data to see how they impact the species composition. for environmental data, I have river discharge, temperature, rainfall, and salinity. ...
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1answer
62 views

How is this connection between Beta and Binomial possible?

I'm learning stats, and I've reasoned about this for many days and I'm losing sleep over it. Say I have a binomial distribution B(k; n, p) simulating a hypothesis <...

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