[R] implicit loop for nested list

[Andrew Simmons]

I would use replicate() to do an operation with random numbers repeatedly:

```
mysim <- replicate(10, {
    two.mat <- matrix(rnorm(4), 2, 2)
    four.mat <- matrix(rnorm(16), 4, 4)
    list(two.mat = two.mat, four.mat = four.mat)
})
```

which should give you a matrix-list. You can slice this matrix-list
just like normal, then cbind it in one step:

```
two.mat <- do.call("cbind", mysim["two.mat", ])
four.mat <- do.call("cbind", mysim["four.mat", ])
```

On Thu, Jan 26, 2023 at 10:33 PM Naresh Gurbuxani
<naresh_gurbuxani using hotmail.com> wrote:
>
> >
> > I am looking for a more elegant way to write below code.
> >
> > #Simulation results have different dimensions
> > mysim <- lapply(1:10, function(y) {
> >    two.mat <- matrix(rnorm(4), nrow = 2)
> >    four.mat <- matrix(rnorm(16), nrow = 4)
> >    list(two.mat = two.mat, four.mat = four.mat) #results with different dimensions
> > })
> >
> > #Collect different components of simulation results
> > #Is it possible to do this with implicit loops?
> > mat2 <- matrix(nrow = 2, ncol = 1)
> > mat4 <- matrix(nrow = 4, ncol = 1)
> > for (mat.list in mysim) {
> >    mat2 <- cbind(mat2, mat.list[["two.mat"]])
> >    mat4 <- cbind(mat4, mat.list[["four.mat"]])
> > }
> > mat2 <- mat2[,-1]
> > mat4 <- mat4[,-1]
>
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