In this article, we will discuss how to sort a matrix according to the first column in R programming language.
Matrix in use:
We can sort the matrix according to a specific column by using the order() function with indexing. To sort according to first column 1 is passed in place of column index.
Syntax:
matrix[order(matrix[ , 1]), ]
where,
- matrix is the input matrix pass with an index
- order() function takes one parameter that is matrix with 1 st column index
Example: R program to sort a matrix according to first column
R
# create a matrix with 4 rows and 5 columns # - 20 elements data = matrix(c(1, 13, 4, 5, 6, 78, 56, 23, 34, 1, 23,
45, 67, 23, 34, 78, 97, 45, 0, 9),
nrow=4, ncol=5)
print("Actual matrix")
print(data)
print("sorted matrix")
# display sorted data according to first column final = data[order(data[, 1]), ]
print(final)
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Output:
Example: R program to sort a matrix according to first column
R
# create a matrix with 2 rows and 2 columns # - 4 elements data= matrix(c(11,2,23,1),nrow=2,ncol=2)
print("Actual matrix")
print(data)
print("sorted matrix")
# display sorted data according to first column final=data[order(data[ , 1]), ]
print( final)
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Output: