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I am wondering how to use apply on a multidimensional array. I have something like the following:
A <- array(0, c(2, 2, 5)) for(i in 1:5) { A[, , i] <- matrix(rnorm(4), 2, 2) } I would like to take the average of those slices to get a single 2 by 2 matrix. Any way I come up with is pretty kludgy.
I was hoping to be able to use apply, like I would if I wanted the average say of the columns of a matrix:
B <- matrix(rnorm(10), 5, 2) B.mean <- apply(B, 2, mean) But this doesn't seem to work the way I think it might with 3D arrays:
A.mean <- apply(A, 3, mean) I appreciate your suggestions.
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Creating a Multidimensional ArrayAn array is created using the array() function. It takes vectors as input and uses the values in the dim parameter to create an array. A multidimensional array can be created by defining the value of 'dim' argument as the number of dimensions that are required.
Apply any function to all R data frame You can set the MARGIN argument to c(1, 2) or, equivalently, to 1:2 to apply the function to each value of the data frame. If you set MARGIN = c(2, 1) instead of c(1, 2) the output will be the same matrix but transposed. The output is of class “matrix” instead of “data.
Apply functions are a family of functions in base R which allow you to repetitively perform an action on multiple chunks of data. An apply function is essentially a loop, but run faster than loops and often require less code.
Create 3D array using the dim() function in R We can create a multidimensional array with dim() function. We can pass this dim as an argument to the array() function. This function is used to create an array. Where, data_inputs is the input data that includes list/vectors.
A.mean <- apply(A, c(1,2), mean) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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