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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0
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1answer
26 views

what does the minus sign mean in the function definition in R [on hold]

I am reading a tutorial and I found a function definition in R ...
0
votes
0answers
6 views

Brand based clustering Fundamental

I am looking to do brand based clustering on our audience (Brand based clusters tell you what brands people like). I have the following data about our customers. ...
0
votes
1answer
42 views
0
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0answers
23 views

Graph with 3 variables in R? [on hold]

I have some data with 3 variables: x = position y = length z = number Here is an example: x y z 12 40 8 13 40 8 14 40 8 15 40 5 16 24 9 I'd like to ...
0
votes
1answer
31 views

How to create and improve a logistic regression model in R

I have to devise a model in R, capable of predicting the type of a disease, which is a categorical dependent variable (three possible values), through several continuous and categorical, some of the ...
0
votes
0answers
3 views

Inverse probability weighting (IPW): standard errors after weighting observations

When using propensity scores for inverse probability weighting (IPW) the standard errors for the parameters in the regression model may be affected. I have seen several examples of people using ...
-1
votes
1answer
32 views

Normal distribution in R: Find the value of $x$ for $P(X=x) = c$ where $c$ is known

I have a normal distribution with parameters $\mu=750$, $\sigma=260$. I'm interested in finding the value of $x$ that satisfies $P(X=x)=0.001$ for both sides of the tail. How would I go about doing ...
0
votes
0answers
13 views

How can I extract a residual variance-covariance matrix in lme?

I have been using MCMCglmm in R to fit bivariate (two response traits) mixed models in R, but now I need to move to lme to account for temporal autocorrelation of the residuals. In MCMCglmm I can fit ...
2
votes
0answers
19 views

Fitting nonlinear meta regression models to data

I have a collection of data, obtained from different studies. To plot the ratio of means against different CO2 concentrations, I used a random effects model with a continues predictor (the CO2 ...
0
votes
0answers
8 views

loop ordinal regression statistical analysis and save the data R [on hold]

I am relatively new to R. The short version of the data looks ike this: ...
0
votes
1answer
38 views

Multivariate OLS - Partialling Out

I have bee wondering why in a multivariate OLS-Regression it is not possible for R² to decrease when increasing the number of explanatory variables. The Point is that for example in the model ...
0
votes
0answers
14 views

How to choose which test to use to determine if a time series is non stationary?

I want to determine if my time series is non stationary. I looked many articles and have learned there is not just one formula - ADF. It seems you must use some series of tests and assumptions. But I ...
0
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0answers
11 views

Bayesian random effects meta-analysis on the risk ratio with r2jags

Following the work of Warn 2002 I am trying to set up the model for a Bayesian meta-analysis on the risk ratio and the odds ratio. I am using R together with R2jags to fit a simple RE MA model. ...
0
votes
0answers
16 views

Failed to reduce deviance while using “lme4 : glmer ”

this is my first post, so I will try to make it as clear as possible. Hopefully is not something trivial and I am just stuck. I am performing meta-analysis using the glmer function of the lme4 ...
1
vote
0answers
17 views

lavaan WARNING: could not compute standard errors!

I have a problem. I use r package "lavaan" to make confirmatory analysis. I run the following code: ...
0
votes
1answer
17 views

Forecasting with no seasonality

I have a set of data, let's say average weight of employees, captured every month over a period of 5 years (2010 - 2014). I cannot find a seasonality trend in the data over these years. Also, I have ...
0
votes
1answer
17 views

Functional clustering with R [on hold]

I have a time series data in R, and I am using functional clustering. I would like to interpret a figure that is output below the code. Furthermore, I would like to control line colors and thickness ...
0
votes
0answers
9 views

stepwise discriminant discriminant analysis with r [on hold]

how do a stepwise variable selection before the discriminant analysis, using the Wilks' lambda criterion, with r? can anybody show me the code? thx
0
votes
1answer
15 views

How to group data into already known centers of clusters in R?

I have a table of GPS data and I need to associate each record to the closest from a list of locations. It's like doing clustering but I already have the centers of the clusters. In this case the ...
0
votes
1answer
12 views

GAM summary F values

Does anyone know how the F values are computed in summary(gam.object). I've looked through the help page, and the gam package, ...
3
votes
1answer
25 views

Comparison of Bernstain and Chebyshev inequalities applied to Bernoulli distribution - simulation in R gives unexpected results

I'm trying to compare Bernstein and Chebyshev inequalities applied to Bernoulli distribution with parameter $p$. More specifically - how good are bounds they give for different sample sizes. I wrote ...
0
votes
1answer
10 views

How do I perform a Wald Test with multivariate Granger Causality Analysis

I am doing a Granger Causality Analysis for three economic variables (GDP, CO2 emissions and Total Energy Consumption) of Puerto Rico. I am using a Toda-Yamamoto Procedure implemented in R R. I am ...
0
votes
0answers
15 views

What does the sigma^2 figure mean when fitting a model to a time series in R?

I have a time series in R, and I am using the arima function to fit it to a SARIMA model. I would like to use the parameters it returns to write the time series equation by hand, but in order to do ...
0
votes
0answers
5 views

RSNNS neural networks, checking percentage correct.

For those who have some experience with RSNNS, I'm trying to build a neural network for reading aloud, using RSNNS in R. To give some information about what I'm doing and using. I'm using orthographic ...
1
vote
0answers
18 views

Overfitting of Regression with Robust Variances?

I performed regression with robust variances (after Stata 12.1 lnskew transformation). A question of overfitting has been raised. To summarise what I did: [1] Comparison of BrS (disgrp=2) vs ARVC ...
0
votes
0answers
8 views

Why are standard errors the same in lag-distributed model in R?

I am running a lag-distributed model ordinary least squares in which a set of units are all treated in the same year. I am including a 2 lags and 2 leads to see if there were any "anticipation" or ...
0
votes
0answers
13 views

Svm for survival analysis in r [on hold]

Is there any implemented package for survival analysis with SVM in R? I need to feed the model with both survival time and event. Thanks!
2
votes
1answer
37 views

Get survival rates from a cox regression in R

I am fairly new to survival analysis and am playing around in R. I have a fairly simple cox model ...
1
vote
0answers
10 views

Efficient Triangular Backsubstitution in R [migrated]

I am interested in solving the linear system of equations Ax=b where A is a lower-triangular matrix (n $\times$ n) and b is a (n $\times$ 1) vector where n $\approx$ 600k. I coded up backsubstitution ...
0
votes
0answers
10 views

How to minimize setup cost in linear programming model using R [migrated]

Suppose we have a matrix m: > m C1 C2 M1 70 80 M2 50 61 M3 45 40 with machines M1-M3 and customers C1-C2. The values indicated the product volume that each ...
0
votes
2answers
23 views

Tests of heteroscedasticity in linear regression models

I am unfamiliar with the implementation used in the R package GVLMA. What are some basic tests of heteroscedasticity in linear regression models and how or where ...
0
votes
0answers
18 views

How is the entropy calculated by the `entropy` package in R?

So, as per the docs, I'm calling the function like this v = c(0,4,3,6,7,3,2,3,4,5) entropy(discretize(v, numBins = 8, r = c(0,7))) and I get ...
0
votes
0answers
6 views

Convert coordinates to neighbor list for spatial analysis in R using INLA [on hold]

I am trying to do an analysis of two greyscale images taken a few seconds apart, where each pixel in the first image should be predictive of the pixel in the second image. In general pixels near each ...
3
votes
1answer
69 views

logistic regression in r with many predictors

I have been running logistic regression in R, and have been having an issue where as I include more predictors the z-scores and respective p-values approach 0 and 1 respectively. For example if have ...
0
votes
0answers
9 views

Using gbm to eliminate variables before glm

I have a classification problem I am attempting to model using logistic regression (via the glm package in R): ...
0
votes
2answers
37 views

Computing R-squared change, F-, and p-values for the interaction / moderation term [on hold]

I would like to compute R-squared change for the interaction/moderation term in a multiple regression model, along with the corresponding F- and p-values. Previously, I have worked with the modprobe ...
7
votes
2answers
205 views

nonlinear regression two equivalent models on paper, but different estimated parameters

I measured one response variable Y1 as a function of two measured independent variables X1 and X2 It is common practice in ...
0
votes
0answers
11 views

correct for temporal autocorrelation in mantel tests

Hej, I want to compare the community composition of a bacterial assemblage with it's resource use ability. therefore I calculate a distance matrix based on the community composition and a distance ...
2
votes
0answers
35 views

Simple importance sampling example: What am I doing wrong?

I am learning about importance sampling and trying undertake importance sampling on a trivial example, but failing to get the right answer. I have read various PDFs online, and the relevant section of ...
0
votes
0answers
32 views

What kind of data types are best to work with prediction algorithms of R

Assuming the data is tidy and it has a mix of columns of type numeric, character and Factor. What is the data type that would give best results when using different prediction techniques in R? I am ...
1
vote
0answers
23 views

Best SQL package for R [on hold]

I am starting programing in R and I am struggling with data manipulation. I am quite fluent in SQL so it would be easier if I could work with a SQL package. Which package would you advice? And why? ...
0
votes
0answers
27 views

Errors-in-variables multivariate polynomial regression (R)

(EDIT: the question has been modified just a little bit to be more specific) I want to fit a multivariate polynomial regression that accounts for measurement errors (an Error-in-Variables model). ...
0
votes
0answers
49 views

Marketing Data with many zeros

I am working on a marketing data which is a time series data with marketing spend done through different channels and revenue generated. The data looks like this : My data contains too many zeros ...
0
votes
1answer
24 views

What is a good test for comparing frequency counts between two groups?

I am looking for statistical methods used to compare frequency of observations between two groups. I have two geographical locations with data on different soil types present. for example, my data ...
0
votes
0answers
15 views

R and MATLAB: Line Plot with Layered Categorical Variables [on hold]

I'd like to reproduce the graph in the attached figure in R and MATLAB. Note that the x-axis contains categorical variables (hour and day). There could be multiple lines in the y-axis (e.g., the ...
2
votes
0answers
31 views

Spearman's rank correlation has p-value zero?

It looks like R's cor.test returns p-values of exactly zero if the real p-value is very low. For example: ...
0
votes
0answers
15 views

Prediction in mlogit [on hold]

I'm trying to use mlogit and predict the choices for my data. My data is: ...
0
votes
0answers
13 views

Permutation to test SNP interactions

sampleID case/ctrl var1 var2 var3 var4 var5... sample1 0 1 0 0 1 0 1... sample2 1 0 0 0 0 1 0... sample3 0 1 1 1 0 0 0... sample4 1 0 0 0 0 1 0... ... case/ctrl status is binary, variant status is ...
0
votes
0answers
20 views

R - Outlier detection multivariate in R [duplicate]

I'm looking for few R packages to detect outliers from a multivariate data frame. In the following Dropbox link you can find an example of data. Columns 1 to 5 are the variables and the 6th the label. ...
0
votes
0answers
2 views

Similarity measurement akin to SMAPE

I have two questions: A) Is there an official name for average of the smaller number over the larger number? B) Why have SMAPE range from 0 to 2? Isn't a range from 0 to 1 superior for understanding? ...