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 program in `R`.

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1
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1answer
25 views

Removing collinear variables for LDA/QDA in R

I'm new to R and I've been searching for a while for a function which can reduce the number of explanatory variables in my lda function (linear discriminant analysis). Basically, I've loaded the ...
3
votes
1answer
60 views

Why does this logistic GAM fit so poorly?

I am trying to create a logistic regression model with mgcv::gam with what I think is a simple decision boundary, but the model I build performs very poorly. A local regression model built using ...
0
votes
1answer
15 views

Density plot narrow peaks and mean far away from peaks

I am trying to understand a density plot. It has narrow peaks and means are far away from the peaks. What would be the reason for such a behavior? Should I be doing a different plot to understand this ...
0
votes
0answers
15 views

non-parametric tests with significant difference in sample sizes

I have outcomes from a biological expt., where we have measured DNA lengths that has been affected. For condition1, I have 11 observations (length of DNA) and for condition2 I have approx. 116000. I ...
2
votes
1answer
19 views

Multivariate hypergeometric distribution in R

Say I have a bag of colored marbles. This bag contains 30 marbles, 2 of which are red, 3 are green and the rest are blue. I am now randomly drawing 5 marbles out of this bag, without replacement. I ...
0
votes
0answers
11 views

Comparison of two correlation matrix of same dimension in R [duplicate]

I have two correlation matrices(Pearson).For example, metrices of (3 gene X 3 gene) for cancer samples and normal samples,individually. I have got gene-gene correlation for both sample. Now I want to ...
0
votes
1answer
15 views

Count the number of each unique row in a data frame? [on hold]

Suppose I have a data frame such like: ...
2
votes
0answers
20 views

Solving non-linear equations in R with optimal inital values

I am using the rootSolve package in R to estimate parameters of non-linear equations. The basic formula is ...
0
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0answers
25 views

SVM accuracy evaluation

Could you please answer some of my questiona regarding SVM-RFE (svm with recursive feature elimination). I am using SVM-RFE with linear kernel for the binary classification and feature selection ...
-2
votes
0answers
28 views

why cannot we find an arima model for the daily forecast of a dataset with more than 2 years of historical data?

I faced this problem a few times. I used TBATS to fit a model to the daily forecast of a variable and then wanted to include other regressors to my forecast. So I used auto.arima. all of my databases ...
0
votes
0answers
8 views

Select the cases from a data.frame that have been used in a GLMM [migrated]

I am trying to see differences in the feeding-rate of one bird species between big forest patches and small ones. I have several forest patches of both sizes, and three years of study. Some ...
0
votes
0answers
19 views

How to solve hat check problem using R? [on hold]

Suppose n people go to a fancy restaurant. Each person is wearing a hat and checks his/her hat at the door as he/she arrives. The hat-check attendant gets tipsy throughout the evening, forgetting ...
1
vote
1answer
45 views

Using MySQL or r, or both?

I have a large dataset and I want to do statistical analysis on certain subsets of the data. At the moment I see this as a two step procedure: Import data into a MySQL database and use the world ...
0
votes
1answer
30 views

sum of correlated random sample

Suppose I have 1000 draws each of two random variables X and Y. If I wanted to sample the sum of these variables, I would simply calculate 1000 samples, i.e. $$ S_{i}=X_{i}+Y_{i}, i=1,2,…,1000 $$ ...
2
votes
0answers
35 views

Imputation of missing values for doing PCA in R [duplicate]

I have a dataset with approximately 4000 rows and 150 columns. I want to predict the values of a single column (= target). The data is on cities (demography, social, economic, ... indicators). A lot ...
1
vote
0answers
30 views

multiplicative model in r

I have to estimate a model forecasting the sales (as stock units) for AXE deoderants.I want to apply the multiplier specification on this model. The model should look like this: log(Sales) = b0 + ...
0
votes
0answers
18 views

Trying to understand the basics of a mixed-effects logistic regression model for a 10-step continuum

I am trying understand how to correctly build a mixed-effects logistic regression model in R. I believe my model is pretty simple and straight forward but I'm lacking in experience and uncertain I'm ...
0
votes
0answers
14 views

Locating minimum on table/output [migrated]

(R studio) Hi, Basic question about how to go about finding the minimum of a value on a table. The table is longer than this (nsplit goes to 1532), which is why I'm looking for a search function. ...
0
votes
0answers
5 views

pggls function in R - weird results

I need to estimate a panel model. I have run the "normal" fixed effects model using plm in R and also wfe. I also wanted to try pggls considering its tolerance of heteroskedasticity and ...
0
votes
0answers
8 views

Value function iteration in R [on hold]

Is there any package in R for value function iteration? Matlab is the weapon of choice for this, but I am an R user. I read the vignettes of many packages, but could not find anything that could help ...
0
votes
0answers
43 views

Logistic Regression: determining significance of independent variables [on hold]

I am trying to do Logistic Regression in R. My data set contains more than 50 variables. Some of them are factor (qualitative variable) and others are independent variable(quantitative). I would like ...
0
votes
0answers
24 views

R code to determine peakedness of a maximum [migrated]

Given input vector $x$, let the maximum of $x$ occur at index $i$ in the input vector. I am trying to quantify the peakedness of this maximum and do that I have thought of determining following ...
0
votes
0answers
15 views

Convergence warnings in glmer

I am running a Generalized Linear Mixed Model in R 3.0.2 using lme4 1.1-7 for a dichotomous outcome variable (success, 0 = no, 1 = yes) ...
1
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0answers
32 views

Linear model / models analysis

Above are three plots of the Linear model I am trying to analyze. The first one is a basic plot of the linear data: ...
0
votes
0answers
19 views

Mixed effects structure: Main effects in random slopes with between-subjects design

My question is about whether it is appropriate to include certain random slopes in a mixed effects model with a between-subjects design. This is my first question on this stack exchange, and I'm ...
1
vote
1answer
18 views

How to assess the functional form of covariates in the Cox model with martingale residuals in R?

I want to find if the functional forms of covariates in my Cox model are linear. I understand the way to do this is to plot the Martingale residuals against the covariate of interest. I have found ...
0
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0answers
5 views
0
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0answers
27 views

I get unusual (wrong) results when plotting regressions with log10 axes compared to linear axes [on hold]

When plotting a datasets of values and then using linear regression I get different (unexpected and seemingly wrong) results when plotting using log10 on both axes. Can someone please help. OK code ...
0
votes
0answers
16 views

Better calculation of ends of the curve when using R's RandomForest?

I've been using R's randomforest library to predict a series of (2000) products with prices ($10-$2000) and I'm noticing the low and high ends of the continuum are least accurate, especially when I ...
2
votes
1answer
35 views

Standardized coefficients for linear models with numeric and factor variables in multiple linear regression using scale() function in R

I have on question regarding standardized coefficients (beta) in linear models. I have already asked one question here. From the answers I assume that I should use R's ...
0
votes
0answers
35 views

lotto simulation with R [on hold]

What is the simplest way to make a lotto simulator. Lets assume that I bought 10 different combinations ( 7 out of 39). So how to calculate the expected value of winning if for 4,5,6,7 correct ...
0
votes
0answers
6 views

klaR package and the stepclass function

(R studio) Hi, I'm running LDA on a dataset with 250,000 observations, 2 classes and 30 variables. My goal is to create a classification model using the LDA function. After loading my variables I ...
3
votes
0answers
47 views

How to best approach ANOVA with multiple response variables that might be correlated and Bonferroni Correction

I need some help verifying a simple analysis. I have completed a simple two factor experiment of more or less equal sample sizes. Let's assume for the case of this question that the sample sizes are ...
0
votes
2answers
50 views
0
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0answers
3 views

R: coherency matrix returned by spectrum is always 1

I am trying to understand what the coh value obtained from a call to spectrum means. I created a random 20x4 matrix and called spectrum on it. The ...
0
votes
0answers
21 views

Reading in data set [on hold]

I am trying to read in this data set using R http://statweb.stanford.edu/~tibs/ElemStatLearn/datasets/nci.data I've tried several different things. Can anyone help me out?
0
votes
1answer
25 views

How to solve nonlinear optimization problem in R

Suppose I have a set of data and reason to believe the following relation holds y ~ a0 + a1*x1 + a2*x2 + a3*log(x3) How can I use R to solve for the coefficients {a0, ... a3}, supposing I want to ...
0
votes
0answers
18 views

Regarding Nested Anova in R

I would just like to double check if my approach to the following analysis was correct. Based on my design I have two treatments (A and B) with treatment A being comprised of 5 populations and B of 3 ...
2
votes
0answers
29 views

“Frequency” value for seconds/minutes intervals data in R

I'm using R(3.1.1), and ARIMA models for forecasting. I would like to know what should be the "frequency" parameter, which is assigned in the ts() function, if im ...
0
votes
0answers
3 views

extract data.frame() from group_by() [migrated]

I'd like extract a data.frame produce by group_by() function of the dplyr package on R. My original data looks like this: ...
0
votes
0answers
18 views

Selecting the right BIC value

I'm using the hddc for an assignment to find the optimal number of clusters. The dataset is 9-dimensional and consists of 200.000 rows, however, the BIC values that I'm getting are really high. How ...
0
votes
0answers
22 views

mixed effect regression model

I would like to expand over a previous question of mine (What is the correct model for this experiment design?), with slight modifications... To set up the scene : We have a completely randomized ...
0
votes
0answers
17 views

Generate observations from an autoregressive process [on hold]

I'm wondering how I could go about generating data from an AR process, for example: $$y_t=0.2+0.5y_{t-1} +e_t$$ where $e_t\sim N(0,1)$ with $y_1=0.2$ I need to generate 100 observations from ...
0
votes
0answers
27 views

Multivariate regression with categorical response variables

Explanation of Data: I started with a data set where each user belong a specific group and their contribution to different domains. After multiple pivots and pre-processing attempts, I got my data in ...
0
votes
0answers
19 views

How to enter data into contingency table directly?

I'd like to create a contingency table. I do it using: matr=matrix(c(62,61,36,19,10,21,58,60,39,22,12,19,91,83,72,23,52,62,43,28,59,57,29,20,12),5,5) but it ...
0
votes
0answers
16 views

Heavy-tailed RBF kernel function

I'm trying to run a SVM regression on some data and I want to use ksvm from kernlab or svm ...
0
votes
0answers
22 views

Phylogenetic General Least Squares, Multivariate Regression

I'm working on a biological question, with species data derived from an external database, which has multiple response and predictor variables. As a result, I want to do multivariate regression across ...
0
votes
0answers
30 views

Determine the causes of change in time with mixed models

I have a database with several continuous variables measured in two times. I searched for a change in time in my dependent variables in this way: ...
0
votes
0answers
58 views

Small loadings in all variables, PCA analysis is ok?

I'm performing a PCA analysis on a set of 5 variables, whose correlation matrix is: ...
0
votes
0answers
22 views

How to interpret ANOVA output comparing two models

I'm working with the Blackmoor data from the study "Female adolescents with anorexia nervosa and their parents." I've made 4 models based on this: ...