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
4 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
votes
0answers
4 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: ...
0
votes
0answers
6 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 ...
1
vote
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 ...
0
votes
1answer
16 views

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

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 ...
-1
votes
0answers
36 views

Multiple linear regression [on hold]

I have a data frame in which I have several columns and rows. For example the data frame below shows column 1 to 4 is my soil moisture data, 5 to 8 is evapotranspiration (ET), and column 9 to 12 is ...
0
votes
0answers
11 views

Regression trees to model rates

I am performing a predictive modeling application where I have to predict claims. If I had used classical GLMs, I would have used a poisson glm using log exposure as offset, assuming therefore ...
2
votes
2answers
82 views

Interpretation of plot(glm.model)

Can anyone tell me how to interpret the 'residuals vs fitted', 'normal q-q', 'scale-location', and 'residuals vs leverage' plots? I am fitting a binomial GLM, saving it and then plotting it.
1
vote
1answer
45 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 ...
1
vote
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 ...
0
votes
0answers
4 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
0answers
13 views
0
votes
1answer
69 views

Measuring longitudinal data where individuals have missing observations

We have a longitudinal panel of X users with their online spending patterns and are trying to measure certain metrics within the panel. We have time series information about the users such as their ...
-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 ...
0
votes
1answer
898 views

predict function and categorical variables in R

This is more of a general question about how the predict function treats categorical variables and how to interpret the output from predict. I have a zeroinfl model to predict the number of animals ...
0
votes
1answer
14 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 ...
1
vote
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 ...
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 ...
10
votes
2answers
963 views

Analyze proportions

I have a dataset containing multiple proportions that add up to 1. I am interested in the change of these proportions along a gradient (see below for example data). ...
0
votes
1answer
46 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 ...
2
votes
1answer
16 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
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 ...
3
votes
0answers
25 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. ...
0
votes
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
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: ...
7
votes
1answer
2k views

Unable to fit negative binomial regression in R (attempting to replicate published results)

Attempting to replicate the results from the recently published article, Aghion, Philippe, John Van Reenen, and Luigi Zingales. 2013. "Innovation and Institutional Ownership." American Economic ...
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 ...
0
votes
1answer
19 views

Correct arguments for svm() function in R

I'm looking to implement a linear and non-linear SVM in R but having some confusion over which argument to use in svm(). For the linear SVM I want to add in the penalty $\gamma$ for soft margin. This ...
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
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
votes
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
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
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 ...
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
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 ...
0
votes
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 ...
3
votes
2answers
3k views

Extract BIC and AICc from arima() object

Problem: I would like to extract the BIC and AICc from an arima() object in R. Background: The arima() function produces an output of results, which includes the estimated coefficients, standard ...
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 ...
0
votes
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
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 ...
3
votes
2answers
732 views

Problems with libRblas.so on ubuntu with rpy2

I try to install rpy2 in my system, (I compile R with --enable-R-shlib and with --enable-BLAS-shlib flags) but when I try in python console import rpy2 import rpy2.robjects I got: Traceback (most ...
0
votes
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 ...
1
vote
1answer
146 views

R plm: understand pmodel.response

I need help in understanding the pmodel.response function from the R package plm. So far I have interpreted this as a way to get ...
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
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
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 ...
0
votes
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 ...
2
votes
1answer
79 views

Change in order of predictors breaks logistic model estimation (glm, R)

I am fitting a binomial logistic regression in R using glm. By chance, I have found out that if I change the order of my predictor variables, glm fails to estimate the model. The message I get is ...