search for: psycwlm

Displaying 11 results from an estimated 11 matches for "psycwlm".

2010 Feb 05
3
metafor package: effect sizes are not fully independent
In a classical meta analysis model y_i = X_i * beta_i + e_i, data {y_i} are assumed to be independent effect sizes. However, I'm encountering the following two scenarios: (1) Each source has multiple effect sizes, thus {y_i} are not fully independent with each other. (2) Each source has multiple effect sizes, each of the effect size from a source can be categorized as one of a factor levels
2013 Apr 09
2
Behaviors of diag() with character vector in R 3.0.0
...rs of diag() for character vectors? Thanks. Mike -- --------------------------------------------------------------------- Mike W.L. Cheung Phone: (65) 6516-3702 Department of Psychology Fax: (65) 6773-1843 National University of Singapore http://courses.nus.edu.sg/course/psycwlm/internet/ --------------------------------------------------------------------- [[alternative HTML version deleted]]
2009 Jun 04
1
Weighted Correlations
How can I calculate a weighted correlation between two variables in R? The command "cor" does not have a subcommand or option for weighting observations. Thanks! josu
2010 May 03
1
Comparing the correlations coefficient of two (very) dependent samples
Hello all, I believe this can be done using bootstrap, but I am wondering if there is some other way that might be used to tackle this. #Let's say I have two pairs of samples: set.seed(100) s1 <- rnorm(100) s2 <- s1 + rnorm(100) x1 <- s1[1:99] y1 <- s2[1:99] x2 <- x1 y2 <- s2[2:100] #And both yield the following two correlations: cor(x1,y1) # 0.7568969 (cor1) cor(x2,y2)
2011 Jun 01
3
error in model specification for cfa with lavaan-package
Dear R-List, (I am not sure whether this list is the right place for my question...) I have a dataframe df.cfa
2011 Jan 07
1
Random Effects Meta Regression
Hi All, I have run a series of random effects meta regressions on binomial outcomes using the metabin function in R. Now I would like to conduct some random effects meta regressions on the outcomes. Is there a command available which will allow for me to test the impact of a certain variable on the relative treatment effect from my meta regressions? Many Thanks, Steph -- View this message in
2008 Mar 03
2
Constrained regression
Dear list members, I am trying to get information on how to fit a linear regression with constrained parameters. Specifically, I have 8 predictors , their coeffiecients should all be non-negative and add up to 1. I understand it is a quadratic programming problem but I have no experience in the subject. I searched the archives but the results were inconclusive. Could someone provide suggestions
2007 Jun 21
3
meta-analysis in R
I would like to combine time-series data to test for correlations and interactions using random and fixed effects meta-analysis. So, I am looking for the right packages and documentation. I know about meta and rmeta packages of R. Are there any more? What are the diffrences in brief? Can you please suggest some references that could be used as a guide for meta-analysis in R (or S-plus)?
2009 Feb 13
2
Meta-Analyisis on Correlations
Dear R-Community, I'm currently trying to find a way to conduct a meta-analysis in R. I would like to analyze data from mostly-cross-sectional survey-studies. The effect sizes would be correlations. The R packages "meta" and "rmeta" are, as far as I can see, set up for analysis with effect sizes for differences (i.e. comparison of the means/odds-ratios of experimental
2011 Aug 17
3
questions about "metafor" package
Hello,   I would like to do a meta-analysis with the package « metafor ». Ideally I would like to use a mixed model because I’m interested to see the effect of some moderators. But the data set I managed to collect from literature presents two limits.   -         Firstly, for each observation, I have means for a treatment and for a control, but I don’t always have corresponding standard
2011 Mar 17
2
Incorrect degrees of freedom in SEM model using lavaan
I have been trying to use lavaan (version 0.4-7) for a simple path model, but the program seems to be computing far less degrees of freedom for my model then it should have. I have 7 variables, which should give (7)(8)/2 = 28 covariances, and hence 28 DF. The model seems to only think I have 13 DF. The code to reproduce the problem is below. Have I done something wrong, or is this something I