How to Convert matrix to a list of column vectors in R ?
In this article, we will discuss how to convert a given matrix to a list of column vectors in R Programming Language. To do this we will take every column of the matrix and store that column in a list and at last print the list.
It can be done in these ways:
- Using the split() function
- Using list() with data.frame()
Method 1: Using split() function:
In this example to Convert a given matrix to a list of column vectors in R we use the split() function.
- The split() function is used to split the data according to our requirement.
- The arguments given in the split() function are data itself and the other one is rep() function
- The rep() function is used to replicates the data and in the rep() function we give one argument i.e. nrow() so, that the sequence is generated row-wise
- In nrow() function we give the data as an argument. “each = nrow()” is used to repeat this process for each row.
Example:
R
# create matrix M = matrix (100:112, ncol=3) # print the matrix display (M) # create matrix to list off column vector l = split (M, rep (1: ncol (M), each = nrow (M))) # print the list display (l) |
Output:
Method 2: using the list() function:
In this example to Convert a given matrix to a list of column vectors in R we use the list() function
- The list() function is used with the “as.” command. This command is used to convert the object into a list and the object can be any kind of data structure i.e. data frame, matrix, vector, etc.
- The argument in the list() function is as.data.frame. So basically, what we are doing here is? At first, we convert a matrix into the data frame by using as.data.frame() then we convert that data frame into the list and at last, print that list.
- In our case what happens is as.list() takes every single column of the data frame and put every element of data frame’s column into a list, store that lists into “l” and prints the l.
R
# creating the matrix M = matrix (100:112, ncol = 3) # print the matrix display (M) # as.list() is used to convert an object into list # as.data.frame() is used to convert as object into # data frame M is converted into the data frame then # that data frame is converted into the list l<- as.list ( as.data.frame (M)) # print the list display (l) |
Output:
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