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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2 views

non-metric multi-dimensional scaling in R: help with plotting and understanding Stress for isoMDS vs. metaMDS

I have a dataframe with 900 observations. There are 11 columns: 9 measured variables and 1 representing region. ...
-1
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0answers
7 views

How to calculate average groups and create columns [on hold]

I want to write a function for the following table Group1 Group2 Age diffG1 diffG2 A K 12 1.33 1 A K 14 1.33 1 A K 16 1.33 1 B M 12 ...
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0answers
6 views

modify Length of Y axis in barplot with R [on hold]

I try to do a barplot with R Here the code hommes <- scan() ...
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0answers
12 views

R language: Can the function rfe of the package caret be used with a mixed effect model [migrated]

I would like to do feature selection with a mixed effect model in R, but I cannot manage to combine the function rfe of the package caret with the function me of ...
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1answer
21 views

Detecting changes in time series (R example)

I would like to detect changes in time series data, which usually has the same shape. So far I've worked with the changepoint package for R and the ...
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0answers
8 views

How to do regression model selection if dummy variables are involved?

Original post on stackoverflow: http://stackoverflow.com/questions/28773153/how-to-do-regression-model-selection-if-dummy-variables-are-involved I am trying to do a logistic regression analysis in R ...
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0answers
5 views

How do I interpret results from calibration using bootstrap in R [on hold]

I am using the package rms in R. I want to report results of the statistics found in the function: ...
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0answers
5 views

Non-recursive regression tree

I would like to construct a regression tree such that each factor appears at most once on each branch. When I use rpart in R, it commonly results in a tree where ...
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0answers
8 views

Monte Carlo for converting data measured using different methods

I have two sets of observations (1 and 2) of the same element, but the methods of measurements were different (say for obs#1 method A and for obs#2 method B was implemented). A subset of samples ...
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0answers
15 views

Is the question of outlier detection to fit a model better? [on hold]

I was searching to find a package in R which has outlier detection since i am a Matlab User; Anyway, I found several questions in this website which the answers disappointed me very much. this is one ...
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0answers
12 views

How do I fit a linear mixed model in R with autocorrelation, when the effect of time is of no interest?

I am attempting to fit a linear mixed model with the lme function using R. My data involve repeated measures, but the effect of time is not of interest to me, so I don't want to include it as a fixed ...
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0answers
13 views

maximizing matrix diagonal elements in R [migrated]

Given a matrix (or table in R ) ...
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0answers
3 views

R Packages for rank-preserving structural failure time model (RPSTM)

I have a randomized clinical trial data that has high percentage(30-40% in both arms) switching over to a different treatment regimen. By browsing through some literature, I am inclined to perform ...
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0answers
3 views

Help with multiple landmark and Non-Metric Data INPUT [on hold]

Thank you all in advance for being so kind as to put up with my extremely beginner level R-Studio (and statistics programming in general) skills. I am struggling with the most basic of tasks-combining ...
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0answers
16 views

How to get standard errors for parameter estimates from full model-averaged coefficients (with shrinkage) [migrated]

I'm using MuMIn to calculate parameter estimates in a model averaging procedure. Right now I want to compare parameter estimates from conditional vs shrinkage. I want to compare both parameter ...
4
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0answers
32 views

When do coefficients estimated by logistic and logit-linear regression differ?

When modelling continuous proportions (e.g. proportional vegetation cover at survey quadrats, or proportion of time engaged in an activity), logistic regression is considered inappropriate (e.g. ...
2
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1answer
17 views

Interpreting results of prop.test()

Suppose that I have two approaches to a particular problem. Approach A is observed to succeed 685 times out of 1347 attempts. Approach B is observed to succeed 2100 times out of 3748 attempts. I ...
0
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1answer
5 views

R : using survey package to run t-test on sub population of weighted data set

I have a large set of weighted data. I have loaded it into a survey design and would now like to run t-tests on sub-populations. example: ...
0
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1answer
48 views

Cross validation for logistic regression in R [on hold]

I am doing a K-fold cross validation for a logistic regression. I first used the PCA to reduce the dimensionality. Then I used those principal components to build the regression model. My problem is ...
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0answers
19 views

Model Stacking algorithm

I'm trying the stacking method to see if it improves my results, but before using some R package, i decided to code it by myself. Here's a pseudocode of what i'm doing: ...
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1answer
48 views

Approach and example of graph clustering in “R”

I am looking to group/merge nodes in a graph using graph clustering in 'r'. Here is a stunningly toy variation of my problem. There are two "clusters" There is a "bridge" connecting the clusters ...
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0answers
8 views

Subset items from a group while controlling for variables between groups

Can anyone offer solutions to the following problem?: I'm trying to extract a subset of items from multiple groups (grouped by 2 separate factors) so that the final groups are: 1) of equal size, and ...
0
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0answers
17 views

best way of univariate prediction for sparse data

I have a client who has sparse hourly data (by sparse I mean there are too many hours with 0 calls). I used TBATS in R to forecast hourly data for them. Regardless of the point forecast, the actual ...
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0answers
14 views

Estimate the conditional distribution of an latent variable?

What techniques might best illuminate the underlying conditional distribution of a latent variable and what information or assumptions would improve that illumination? For example, if we have data ...
0
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1answer
18 views

Calculating Standard Deviation when given sample size, mean difference & p value

I am trying to pool data in my meta-analysis and i need MEAN & SD. However the study has reported sample size (27), before (11.8) & after mean (11.9), and p value (0.540). I need the SD. ...
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0answers
14 views

Choropleth / thematic map in R with ggplot2 not filling polygons [migrated]

I am doing the following: I read a shapefile containing boundaries within a city (Leeds for example), then I read another data set (csv.) containing the number of females in each area for which I ...
0
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1answer
35 views

Relation between $R^2$ and the covariate correlation matrix

I'm quite new to Statistics and I'm facing a problem. Is there any relation between $R^2$ and the correlation matrix of the covariates? A short example is (case with 2 covariates) : A7 ~ A1 + A2 ...
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0answers
19 views

Can I use gzlm with Poisson family if counts data are treated as factors? [on hold]

My data called (my data) looks like below and I have 5 DVS(dv1,dv2,dv3,dv4,dv5) note all under one column and three IVS(IV1,IV2,IV3) as a data frame. I keep getting the error below. I am trying to fit ...
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1answer
18 views

Logistic regression: Overall significance of categorical predictor in SPSS

In SPSS, when performing binary logistic regression using multiple categorical predictors, a significance level is detailed for the variable overall in addition to each category. This strikes me as ...
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0answers
5 views

How to test/validate unlabeled data in association rules in R?

I produced association rules by using the arules package (apriori). I'm left with +/- 250 rules. I would like to test/validate the rules that I have, like answering the question: How do I know that ...
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0answers
19 views

How do test that two continuous variables are independent using rank statistics in R? [on hold]

This question a particular case of this question. Suppose we have a sample $(X_i,Y_i),i=1,\ldots,n$ from the joint distribution of $X$ and $Y$. Are there any other function (or package) apart from ...
0
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0answers
23 views

Regression of Higher order [migrated]

I want to fit a model $Y = X_1^2 + X_2^2 + X_1 + X_2 + X_1\cdot X_2$ How to build this in R glm(Y ~ poly(X1,2) * poly(X2,2) how to generalise it to higher order ...
2
votes
1answer
30 views

One sample test of uniformity in R

I have a dataset of two columns: one with IDs and one with a column of single digits (0-9) (see below). I would like a statistical significance test for whether the data is uniform. Ideally, I would ...
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0answers
6 views

Adjusting for outlier in Fractional logit in R when dv is very small proportion

I used the code from this site: http://stackoverflow.com/questions/19893133/fractional-logit-model-r to estimate a fractional logit model. There are 90 observations in my dataMy dependent variable is ...
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0answers
7 views

Using different sets of binary indicators based on another indicator - R, linear regression

I'm trying to come up with a prediction model for an output based on the hour of the day. I already have a simple model that predicts the output based on 23 factors that represent each hour of the day ...
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0answers
6 views

Zero-inflated mixed models with two-stage fitting

Zero-inflated models have a count component (Poisson/Neg. Binomial) and a zero component (logistic regression part). glmmADMB supports the zero-inflation feature but only through estimating a ...
2
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0answers
28 views

Does my yeast population split?

Description of the data Imagine a population of yeasts that move along 1 dimension through time. They may move more or less randomly and eventually at some point the population will more or less ...
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1answer
19 views

Critical value for Wilcoxon one-sample signed-rank test in R

I am trying to find the critical value for the Wilcoxon one-sample signed-rank test. Currently, I can find the value using tables. I looked at qwilcox() in R, but ...
0
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0answers
11 views

Is this R code of Rao score test for the Bernoulli data model correct? [migrated]

I am a complete statistical noob and new to R, hence the question. I've tried to find an implementation of the Rao score for the particular case when one's data is ...
0
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0answers
12 views

Penalized ML estimation of non-linear probit

I have a model of the form $P(y_i=1) = \Phi(\frac{w_1^{\beta'x_i}-w_2^{\beta'x_i}}{\sigma' x_i})$ where $y_i$ is a binary response, $\Phi$ is the normal CDF, $w_1$ and $w_2$ are non-negative ...
0
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0answers
11 views

Degrees of freedom clarification [duplicate]

I'm new to statistics, and so far I'm not grasping the significance of the concept of "degrees of freedom". So far, I've only had tangential exposure to it by way of calculating Student's t. When we ...
0
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0answers
10 views

Bias linear regression R [on hold]

Consider a linear statistical model: y = a + bx1 + cx2 + e The parameters are a, b, c and sd(e), The analysis is focused on valid estimation of b. If cov(x,z) =/= θ, and z is excluded from the model ...
0
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1answer
18 views

Systematic Sampling with unequal probabilities

I found the library Sampling in R to conduct a systematic random sampling with unequal probabilities. I got my sample but I really don't know how that sample is selected. Is there anyone that can ...
0
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0answers
10 views

Simulation Record Values from a Continuous Distribution [on hold]

The records in a series of observations are those values which are more or less than their previous values.how can we generating this values in R?
2
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1answer
32 views

How to interpret VIF?

I am using the vif function in the R package car to test for multicollinearity. I am a little confused at the output given. For example, I have 5 variables (x1, x2, ...
0
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0answers
17 views

Kruskal-Wallis and post-hoc analysis in R

Although I know there are several post in this forum that are about this topic, none of them was useful in my case. I have the next data: ...
0
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1answer
31 views

Normalize time series with different lengths with linear interpolation in R

I have a large set of time series (100k, each 3 observations), their lengths varies about 10% on average. Each of them cover the time interval of the same lengths but varies due to rate of sampling, ...
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2answers
53 views

Random intercept turns insignificant - Interpretation

I am running a intercept model with intercepts varying across people in R. My independent variables are all numeric variables. My question is a general one: I saw already that it can happen that my ...
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0answers
13 views

unit root test for seasonal data [migrated]

How to perform unit root test for seasonal data series by using Eviews and R software? i've tried R code provided by Rob J Hyndman in OTexts, but still can't use.
2
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0answers
13 views

Prediction intervals for mixture models for time series forecasting - is it really an average of the prediction intervals of the averaged models?

I'm trying to find out how to do forecasting with a mixture model (averaging the forecasts of an ets, an arima and an ...