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How to save an object generated by "assign" function as .RData file in a loop? Here is an example.

for (ii in 1:3){
QQ=matrix(runif(15),5,3)
assign(paste0("FF", ii),QQ) 
}
Nile
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  • `library("fortunes"); fortune(236)` https://stackoverflow.com/questions/17559390/why-is-using-assign-bad?s=6|45.4089 Learn to use lists: `QQlist <- lapply(1:3, function(ii) matrix(runif(15),5,3))` or `QQlist <- replicate(3, matrix(runif(15),5,3), simplify = FALSE)` – jogo Aug 07 '18 at 06:58

1 Answers1

2

Personally, I find that .RDS files are better suited to save single objects. For instance:

for (ii in 1:3) {
    QQ = matrix(runif(15), 5, 3)
    object_name <- paste0("FF", ii)
    assign(object_name, QQ)
    tmp_fle <- tempfile(pattern = object_name, fileext = ".RDS")
    print(tmp_fle)
    saveRDS(
        object = get(x = object_name),
        file = tmp_fle
    )
}

Given the results:

# [1] "/var/folders/7x/kwc1y_l96t55_rwlv35mg8xh0000gn/T//Rtmpsj0j8h/FF1afe6b0a300.RDS"
# [1] "/var/folders/7x/kwc1y_l96t55_rwlv35mg8xh0000gn/T//Rtmpsj0j8h/FF2afe369d586e.RDS"
# [1] "/var/folders/7x/kwc1y_l96t55_rwlv35mg8xh0000gn/T//Rtmpsj0j8h/FF3afe1418b9c5.RDS"

To access second of the saved objects:

>> readRDS("/var/folders/7x/kwc1y_l96t55_rwlv35mg8xh0000gn/T//Rtmpsj0j8h/FF2afe369d586e.RDS")
           [,1]      [,2]      [,3]
[1,] 0.38537636 0.2969078 0.9603315
[2,] 0.08339023 0.9127538 0.6552166
[3,] 0.55220069 0.4384881 0.5345182
[4,] 0.10179912 0.6353755 0.8247961
[5,] 0.63983736 0.8858784 0.8904668
Konrad
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