Suppose I have following list : mat <- vector("list") for (i in 1:4) mat[[i]] <- matrix(rnorm(25),5) mat
> mat [[1]] [,1] [,2] [,3] [,4] [,5] [1,] -1.27171814 -0.8087277 -0.4771356 0.6001265 0.9842248 [2,] -1.37337445 1.0754536 -1.6304287 -0.6854075 -0.6029390 [3,] -0.32393457 -0.8933633 -0.9077967 0.9738039 -3.0220266 [4,] -1.22184968 -1.2571625 -0.4064736 -1.6686981 -0.4896512 [5,] -0.09333244 1.4880530 1.6410411 -0.5489993 1.0939736 [[2]] [,1] [,2] [,3] [,4] [,5] [1,] -1.0139178 -0.4817983 -0.2141111 0.1649356 1.7750268 [2,] 1.5544890 0.6345386 1.6307417 -2.0887206 1.8299279 [3,] -0.3575260 -0.6669547 0.5960779 -1.1091696 -0.2831409 [4,] 0.7742701 0.8313172 0.4178063 -2.5993914 -0.9920140 [5,] -0.6238547 0.8777678 -1.4249051 -0.4793574 0.5290309 [[3]] [,1] [,2] [,3] [,4] [,5] [1,] -1.2833578 0.2271013 -1.605616640 0.3379672 0.86307678 [2,] 0.8928252 -0.2826024 -0.294600779 0.3659292 -0.06884467 [3,] -0.8237363 1.2258510 1.091578624 1.6907392 -0.42073560 [4,] -0.2537396 0.3662041 0.009558159 1.2127068 -1.14449393 [5,] -0.5001592 0.5390412 0.372628875 -0.9434233 -0.52022201 [[4]] [,1] [,2] [,3] [,4] [,5] [1,] 0.55638191 2.000902039 -0.40155111 0.6214637 0.4044958 [2,] 0.06705861 -0.005629049 0.05144204 0.4910031 -0.2711823 [3,] -2.07173018 -0.210809259 0.22680564 0.5624870 -2.1322234 [4,] 0.04591303 -0.735466145 -0.13164334 -1.8873585 -1.2711131 [5,] 0.67454754 0.911601123 1.34304395 2.2798986 -0.5136242 Define another vector : vect <- rnorm(4) Now I want to do following calculation for (i in 1:4) mat[[i]] <- mat[[i]] * vect[i] mat My question is, can I do previous calculation without having "for" loop? Thanks -- View this message in context: http://www.nabble.com/A-question-on-List-tp25075922p25075922.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.