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`.

learn more… | top users | synonyms

0
votes
0answers
5 views

Growth mixture modeling with latent variables in R with lcmm

I am trying to replicate the analysis that was used to make this figure: I have measured the depression levels (a quantitative variable) in my subjects at the following time points (in months): ...
0
votes
0answers
9 views

Simulating Random Vector X in R to Confirm with Example that cov(AX) = A cov(X) A'

As has been answered previously, the proof of cov(AX) = A cov(X) A' with X being a random vector and ...
0
votes
0answers
26 views

Interpreting regression results

I computed the following regression using R. ...
0
votes
0answers
15 views

Clustering data with one feature

Is there any built in method to cluster data with one categorical dimension in R? Basically, I have a data set including week of the year and if an event happened in that week. I wanted to use ...
0
votes
0answers
11 views

Estimating Mutual Information using R

I am trying to estimate the mutual information between vit level (values vary from 4 to 70, all of which are whole numbers) and a binary variable that indicates the presence of polyps. I am not sure ...
0
votes
0answers
10 views

How to report the group means and TukeyHSD for an ANOVA without intercept in R? [on hold]

I would like to run a Two-Way ANOVA without the intercept, and be able to report the grand and group means, and run TukeyHSD. However, I would receive this error. ...
0
votes
1answer
7 views

Computing the predicted value from a panel data model with the plm R package

I am estimating the following panel data twoways fixed effect model: y = alfa*y.lag + beta1*z + beta2*z^2 + theta*id + gamma*t (1) where ...
0
votes
0answers
8 views

How to test the significance of the Hurst parameter?

I am trying to fit a FARIMA model and I am using rsFit function in R to estimate the Hurst parameter (H). This function provides ...
0
votes
0answers
15 views

out-of-sample variance calculation using rolling window in R

My objective is to calculate out-of-sample variance of various portfolios. I am currently working on the comparison of the constructed portfolios using ...
1
vote
0answers
22 views

Neural Network-Fitted values [on hold]

I need to train a Neural network on a set of data. I used several different packages in R, like 'nnet', 'neuralnet', 'elmNN'. I'm looking for a way to do it in R so that I can access all the weights ...
0
votes
0answers
24 views

Predict out of sample values for support vector machine

I wonder how I can use the results for svm() in R for out of sample predictions. Assume that we split the dataset into train and test sets and use ...
0
votes
0answers
15 views

Copula for multivariate distributions

Is anyone know how to join two multivariate distributions using copulas in r. For example let $X=f(x_1,x_2, \ldots,x_n)$, $Y=f(y_1,y_2,\ldots,y_n)$ I need to find a copula for joining $X$ and $Y$ ...
0
votes
0answers
13 views
1
vote
1answer
59 views

Probability help needed

I have a R data frame (>2000 obs) ...
1
vote
1answer
122 views

R Time Series Analysis forecast result always remains same

I am trying to do time series analysis in R. I have data time series data set like this. ...
0
votes
0answers
8 views

Including class probabilities might skew a model in caret?

I've been training SVMs over some particular data for some time. I was quite happy with the Kappa and Accuracy measures caret gives, but adding some other metrics was not a bad idea at all. The thing ...
1
vote
0answers
25 views

How to simulate data in R given mean, median, and range?

I would like to simulate n numbers (all within the range between a and b, n being an even number) using R, and the mean (u) and median (m) is given. If I use runif then the standard deviation is ...
0
votes
0answers
7 views

Indicator species analysis in R (labdsv package) [migrated]

I am trying to do indicator species analysis in R using the labdsv package. I was able to get it to work on previous sequencing data set but now it has thrown ...
0
votes
0answers
18 views

Specification of mixed model structure in glmmLasso

I am having difficulties specifying the appropriate structure for nested/random effects in a mixed model that I am trying to pass through the 'Lasso' shrinkage algorithm. I am using the package ...
0
votes
0answers
6 views

R: dichotomous time interaction in a Cox model

I am using the Cox proportional hazards model to estimate adjusted hazards ratios for survival data. My main effect violates the proportional hazards assumption. I understand there are several ...
1
vote
0answers
7 views

Data frame manoeuvre [migrated]

Suppose I have the following dataframe: ...
0
votes
0answers
13 views

H2O's deep learning on R has a confusion matrix problem…?

I am testing H2O's deep learning in comparison with random forest in R. When I used (1) IRIS dataset [150 observations/samples by 4 predictors/features; the last column shows the class labels (iris ...
0
votes
0answers
9 views

How to calculate linearized rate of postoperative complications in % patient/year in r [on hold]

Linearized rate is a method summarise constant hazard function in a very simple way and defined as: total number of observed events divided by total patients-year (person-year). These rates should be ...
1
vote
0answers
32 views

Fit and evaluate a second order transition matrix (Markov Process) in R?

I already built 1 first order discrete state Markov Chain model. It was built with R using the function 'markovchainFit()' in ...
0
votes
0answers
19 views

Phi correlation for multiple cells

I have this table for chi-square in R: x <- matrix(c(23,22,10,14,11,12),ncol=3) phi(x) this is a 3 by 2 table and thus phi correlation won't work here, can ...
0
votes
0answers
16 views

Modelling proportional hazards in Cox Model using coxph in R

Assume I have a heterogeneous sample with two categorical variables A and B, each with 2 levels. Now I want to measure the effect of these on the survival function. So we assume proportional hazard, ...
1
vote
0answers
21 views

How do I plot an abline() when I don't have any data points (in R) [migrated]

I have to plot a few different simple linear models on a chart, the main point being to comment on them. I have no data for the models. I can't get R to create a plot with appropriate axes, i.e. I ...
3
votes
1answer
40 views

Introductory data trend analysis with R [on hold]

I am new to the data analysis world and am struggling to find relevant articles / examples related to what I'm trying to do. I have a data set that is like this, for example how many apples are sold ...
2
votes
1answer
39 views

Best way to deal with heteroscedasticity in R?

Originally posted on stackexchange but I was told that it fits better here. I have a plot of residual values of a linear model in function of the fitted values where the heteroscedasticity is very ...
1
vote
0answers
19 views

Best way to deal with heteroscedasticity in R?

I have a plot of residual values of a linear model in function of the fitted values where the heteroscedasticity is very clear. However I'm not sure how I should proceed now because as far as I ...
2
votes
1answer
39 views

R Own Implementation of Cross Correlation using Convolution

I try to implement my own cross correlation function in R by translating it as a convolution problem. Part I: So I have two arrays, e.g. two identical arrays, and I want to get the cross correlation ...
1
vote
0answers
95 views

^ symbol in lm() in R [migrated]

I asked this question in Stack Overflow: http://stackoverflow.com/questions/29710525/symbol-in-r-lm I feel like here would be a better place to get an answer. What exactly does the ^ symbol do to the ...
0
votes
0answers
13 views

How to allocate questions to factors using R output?

I have the R output below, but don't know how to allocate questions to the factors. Any advice? ...
0
votes
0answers
10 views

Frequency analysis from time dependent data in R

I've got a time dependent data from animal recording. My data has two groups (TR and UT) each group has 20 replicate. Tiempo (time) variable goes from 282 sec to 318 sec. I have a turning point at 300 ...
0
votes
1answer
30 views

What is the baseline level in a factor-by-factor interaction?

What is the baseline level for a factor-by-factor interaction term in multiple regression? Consider this example from Fox 2003. In the regression below, these two variables are categorical: ...
0
votes
0answers
21 views

Anova (missing F statistics), Ancova and mixed modelling on nested dataset

I am performing an analysis in R and wonder how to do it since different methods return very different results. My dataset contains Samples and SubSamples as nested random effects and Type, Dose and ...
1
vote
0answers
12 views

Variance matrix for model errors

I am having trouble with understanding how can I write out the variance matrix for model residuals. I have a very simple data with 6 observations: ...
0
votes
1answer
27 views

R: how to separate date-time data types [on hold]

My data set is "weather": I need to calculate the average time and date. First I tried to separate the date and time into to different columns by: ...
1
vote
0answers
29 views

What are the best packages for Image Processing in R? [on hold]

I just have started working on an image processing and classification problem. I am familiar with both R and Python. But I am not much experienced in scikit-learn and scikit-image libraries in Python. ...
1
vote
2answers
35 views

R: how many equal letters between two strings [on hold]

I have 2 strings: "aaaabbC" and "adgfccc" I want to know how many letters appear both in the first and second string (and not how many times a letter apears) in my example, the answer will be: 2 ...
1
vote
1answer
19 views

beta-binomial distribution with R

I am studying an experiment of the kind: Let $n_{ij}$ be the number of fetuses, $X_{ij}$ the number of responses i.e. the number of fetuses with a malformation in the jth litter of the ith dose level ...
1
vote
1answer
17 views

Smoothing Kernel Preventing Simulation of Semi-Circle Law of Random Matrices

In trying to understand the properties of random matrices in the book "Plane Answers to Complex Questions" by R.Christensen, I came across the Semi-Circle Law, and tried to reproduce it with ...
0
votes
1answer
15 views

Blocks in a given numeric vector [on hold]

Given a sequence of integers: 1,1,2,3,1,3,4,5,6,2,2,2,7. It is required to report the no. of occurrences of each integer {1,2,3,4,5,6,7} but block-wise. Block-wise means an integer occurring in the ...
-1
votes
0answers
19 views

how to divide my categorical data into three clusters [on hold]

I have some data of 10 attributes, all of which are categorical attributes (factors in R). I would like to divide this data into three homogeneous sets(clusters). I went about doing 3-means ...
0
votes
0answers
19 views

R - replace TRUE with actual value [on hold]

My goal is to mark the values in plot if the value of jj is less than min_threshold and greater than ...
1
vote
1answer
20 views

Algorithm and R code for dealing with ties in Wilcoxon rank-sum test

1) I think one of the algorithms used to handle ties for the Wilcoxon rank-sum test (a.k.a. Mann-Whitney U test) is Streitberg / Rohmel. I could not find a good source which explains the algorithm/ ...
0
votes
0answers
4 views

Model diagnostic tests for local linear regression

What are some of the model diagnostic tests which are used/ would be suitable to use for a local linear regression model? Note that this is not the least squares linear model, but rather a special ...
0
votes
0answers
11 views

How to interpret a multilevel model that repeats variables for fixed and random effects (like in MCMhregress)?

I came across a specification of a multilevel model that I'd never seen before. It looks like the R function MCMChregress (see: ...
1
vote
0answers
16 views

Binomial data: Null Hypothesis $p = 0$ when all Sample Values are 0 - testing and power analysis

I am trying to investigate if the proportion of successes in my population can be shown to be larger than zero. Thus, $H_0: p = 0$ and $H_A: p>0$. Since $p=0$, the prop.test in R does not work, ...
2
votes
1answer
27 views

Visualise variance partitioning

I'm interested in visualising variance partitioning in the context of linear models. Say you run an linear regression that predicts peoples weight based on their height and age. How can you visualise ...