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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0answers
6 views

Scatterplot with two different categories of data

I have a text document containing three columns. One column is "sex", and each value is either "M" or "F". The other two columns contain numerical data (my explanatory variable and response ...
0
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0answers
6 views

Time series analysis for discontinous years

i have a data of measured values of pH in river water for two years 2004 and 2009 for each month. I want to see seasonal trend ie: are there similarity in summer , winter and monsoon for both year. ...
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0answers
9 views

Paired homogeneity test: Compare two regression coefficients in R

I have a question about paired homogeneity test. By using Cox regression analysis Im evaluating 2 new biomarkers (A and B) in association with a outcome (X). I developed 2 multivariable models and on ...
0
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0answers
17 views

Multiple imputation of conditional variables

I need to impute the missing values of a dataset of medical data in which several variables only make sense if another variable has a specific value. In the questionnaire the data come from they were ...
0
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0answers
9 views

partial plots from a Random forest classifier for binary predictors

I'm working on a classification problem with continous and categorical predictors with Random Forests (RF). I'm particularly interested on RF as we avoid the specification of the functional form. ...
0
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0answers
7 views

should we check for multicollinearity when building a discrimination analysis?

In fact, I have two questions: 1- do we need to check for the multicollinearity when we deal with linear discrimination analysis? 2- how to solve those variables which are multi-collinear? Lets ...
2
votes
1answer
11 views

Advantages of counterbalancing vs. randomizing stimuli

I'm designing an experiment, in which 40 participants answer 10 questions, 5 in condition $A$ and 5 in condition $B$, and I'm interested in the difference between the two conditions. It's not clear ...
-1
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0answers
27 views

Optimal brain damage in R

Is there any R package implementing optimal brain damage algorithm or anything similar what can be used to prune neural networks models?
0
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1answer
21 views

Setting up a aov model in R for a variant of a 2-way nested ANOVA

I have a rather complex experiment i need to analyse The experiment was an infection trial, where the effect of two different infection methods ("inoculation" and "in-contact infection") were ...
0
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0answers
7 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
9 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 ...
-1
votes
0answers
9 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() ...
0
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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 ...
5
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4answers
68 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 ...
0
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0answers
10 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 ...
0
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0answers
9 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: ...
1
vote
0answers
10 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 ...
0
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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 ...
0
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0answers
24 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 ...
1
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0answers
13 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 ...
0
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0answers
13 views

maximizing matrix diagonal elements in R [migrated]

Given a matrix (or table in R ) ...
0
votes
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 ...
0
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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 ...
0
votes
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 ...
6
votes
0answers
46 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
votes
1answer
18 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
votes
1answer
9 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
votes
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 ...
0
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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: ...
1
vote
1answer
49 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 ...
0
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0answers
9 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
votes
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 ...
0
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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
votes
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. ...
0
votes
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
votes
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 ...
-1
votes
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 ...
1
vote
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 ...
0
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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 ...
0
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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
votes
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
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1answer
35 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 ...
0
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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 ...
0
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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 ...
0
votes
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
votes
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 ...
1
vote
1answer
20 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
votes
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
votes
0answers
16 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
votes
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 ...