search for: stacklistitems

Displaying 3 results from an estimated 3 matches for "stacklistitems".

2012 Jun 12
0
Working on a Vignette called Rcheology
...This, Not That" bits, but it is hard to find particular approaches that almost all of you will agree to. Almost everybody agrees that calling rbind over and over again is slow, and do.call with rbind and a collection of stackable things is better: http://pj.freefaculty.org/R/WorkingExamples/stackListItems.R If you have ideas for "Do This, Not That", I'd be glad to hear them and I'll look for example applications that make them relevant. pj -- Paul E. Johnson Professor, Political Science ? ?Assoc. Director 1541 Lilac Lane, Room 504 ? ? Center for Research Methods University of K...
2010 Sep 09
0
Fast / dependable way to "stack together" data frames from a list
...speed can be found if we convert this into matrices, but that is not possible if the list actually contains data frames. I've run this quite a few times, and the relative speed of the different approaches has never differed much. If you run this, I hope you will feel smarter, as I do! :) ## stackListItems.R ## Paul Johnson <pauljohn at ku.edu> ## 2010-09-07 ## Here is a test case df1 <- data.frame(x=rnorm(100),y=rnorm(100)) df2 <- data.frame(x=rnorm(100),y=rnorm(100)) df3 <- data.frame(x=rnorm(100),y=rnorm(100)) df4 <- data.frame(x=rnorm(100),y=rnorm(100)) mylist <- list(df1...
2012 Jul 03
2
EM algorithm to find MLE of coeff in mixed effects model
I have a general question about coefficients estimation of the mixed model. I simulated a very basic model: Y|b=X*\beta+Z*b +\sigma^2* diag(ni); b follows N(0,\psi) #i.e. bivariate normal where b is the latent variable, Z and X are ni*2 design matrices, sigma is the error variance, Y are longitudinal data, i.e. there are ni