1) dmatrix1<-function(n,p,rho,sigma,k){ muvec1=zeros(1,p) truep<-as.matrix(c(3,1.5,0,0,2,0,0,0)) A=eye(p) for(i in 1:p){ for(j in 1:p){ A[i,j]=rho^(abs(i-j)) X=mvrnorm(n,muvec1,A) y=X%*%truep+as.matrix(rnorm(n,0,sigma)) Y=X[1:k,] w=y[1:k] Z=X[(k+1):n,] z=y[(k+1):n]}} return(list(X,Y,w,Z,z)) } I made this code which performs design matrix.. Can you help me how to make several data set....?? the code i made compute only one data set...
2) we generate 50 data with 30 variables. The true regression vector is such that bj = 3 − 0.1j j = 1, . . . , 10, bj = −5 + 0.3j j = 20, . . . , 25, bj = 0 for the others j. The noise is such that sigma = 9 and the correlations are such that (j, k) = exp (−|j−k|/2 for (j, k) ∈ {11, . . . , 25}2 and the others variables are i.i.d. N(0, 1), also independent from x11, . . . , x25 how to simulate this data set.... 3)we simulated 50 data sets and 40 predictors. β=(3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0) and σ=15. The predictors X were generated as follows: xi=Z1+"xi , Z1∼N.(0,1), i=1, . . . ,5, xi=Z2+"xi , Z2∼N.(0,1), i=6, . . . ,10, xi=Z3+"xi , Z3∼N.(0,1), i=11, . . . ,15, xi∼N.(0,1), xi independent identically distributed, i=16, : : : , 40 how to simulate this data set.... -- View this message in context: http://r.789695.n4.nabble.com/hi-l-have-a-question-please-help-me-tp2307569p2307569.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.