Search Results
Search type | Search syntax |
---|---|
Tags | [tag] |
Exact | "words here" |
Author |
user:1234 user:me (yours) |
Score |
score:3 (3+) score:0 (none) |
Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
Views | views:250 |
Code | code:"if (foo != bar)" |
Sections |
title:apples body:"apples oranges" |
URL | url:"*.example.com" |
Saves | in:saves |
Status |
closed:yes duplicate:no migrated:no wiki:no |
Types |
is:question is:answer |
Exclude |
-[tag] -apples |
For more details on advanced search visit our help page |
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`.
3
votes
1
answer
395
views
anova() for lm() object returning inconsistent results
Below is a brief snippet of R syntax. If you run it, you will see that model 2 v model 3 produces the same F ratio in each output. However, model 1 vs model 2 produces different F ratios. …
1
vote
R Difference between rbinom and sample
Yes, these functions appear to generate the same output. To more clearly see this, try the following code
n <- 100
seed.val <- 3
set.seed(seed.val)
x <- sample(c(0,1),n,replace=T,prob=c(19/37,18/37) …
2
votes
GEE interpretation
The Wald $\chi^2$ test statistics are just the squares of the $z$ test statistics you have in the R output. In this case, the $P$-values will should be the same. …
1
vote
Accepted
Doing a chi squared test in R
Using R, the correct code would be
chisq.test(v,p=freq)
When I attempted to run this test, there was a problem:
Chi-squared test for given probabilities
data: v
X-squared = 16939, df = 25, …
2
votes
What do I do with local dependence in a polytomous IRT model?
From what you've described, my inclination is that you have item redundancy. Look at how highly correlated the flagged polygamous items are. If they are highly correlated, then you can consider just d …
2
votes
Interpretation of R2 from PERMANOVA (adonis2) in vegan package
The $R^2$ values reported are indeed coefficients of determination, but they are all partial-$R^2$s (of at least the second-type). … That is to say, the partial $R^2$ values reported most likely will not sum to 100%. …
2
votes
Interpretation of standardized coeffizients (beta) for interactions in linear regression
This is an issue of linearizing non-linear problems. (A strange response, and I'll briefly elaborate before providing an answer.) We can solve polynomial regression using linear regression because w …
2
votes
What does the P-value tell me in this case?
The plot is providing a graphical representation of the chi-square test for independence. (In the 2x2 context, the same test as asking if two groups have the same proportion.) The null hypothesis is t …
2
votes
How to construct a 90% confidence interval for the standard deviation of a set in R?
The first value is the right-side critical value $\chi_{R,cv}^2$; the second value is the left-side critical value, $\chi_{L,cv}^2$. … , you need to take the square root of everything in the trilinear inequality:
$$\sqrt{\frac{(n-1)s^2}{\chi_{R,cv}^2}} < \sigma < \sqrt{\frac{(n-1)s^2}{\chi_{L,cv}^2}}$$
If there is an R function, maybe …
1
vote
How can I plot a hyperbolic curve in R and get an equation of best fit?
If you assume that your data follows a hyperbolic model, then you can use the following approach (detailed more here https://engineerexcel.com/hyperbolic-curve-fitting-excel/):
use a harmonic transfo …
2
votes
Heywood Case in Exploratory Factor Analysis (in R)
You will need to look at the standardized solution. In that output, you should have an estimate for the variance for the items in the model. One of them has been flagged as having an impossible varian …
2
votes
What's the fundamental difference between these two regression models?
First, I will introduce yet a fourth model for the discussion in my answer:
fit1.5 <- lm(y_2 ~ x_1 + x_2 + y_1)
Part 0
The difference between fit1 and fit1.5 is best summarized as the difference b …
0
votes
Meta-Analysis help with next steps
For a meta-analysis of this sort, the idea is to combine the effect size information from your disparate samples into one measure for the effect size. The conventional protocol here would be to estim …
2
votes
Collinearity in polynomial regression
Introduction of higher powered terms will invariably result in issues of multicollinearity. This is essentially unavoidable. Thus, it is best to only include the terms if theoretically justifiable. …
1
vote
R-Square Change in a Multivariate Regression
In this case, you can obtain an $R^2$ for the latent variable, and you can do an F-test with the two different models (2 iv's vs. 3 iv's). …