Page 230 - Data Science class 11
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Thus, matrices are an extension of numeric or character vectors. In other words, they are atomic vectors arranged in
a two-dimensional rectangular layout. As a matrix is an atomic vector extension, its elements must be of the same
data type.
To create a matrix in R, we use the matrix() function.
6.9.1 the syntax for creating a matrix in r is:
matrix(data, nrow, ncol, byrow, dimname)
The parameters used in matrices are as follows:
• data: the input vector which becomes the data elements of the matrix.
• nrow: number of rows to be created.
• ncol: number of columns to be created.
• byrow: represents a logical clue. When it is set to TRUE, then the elements in the input vector are organised by row.
• dimname: is the names assigned to the rows and columns.
#Example of a matrix with no data source
Example
Enter the following code snippet:
y <- matrix(nrow = 2, ncol = 2)
y
Results obtained when the code above is run:
NA means data not available.
6.9.2 creating a matrix taking a vector of numbers as input.
Example
Enter the following code snippet:
# Elements will be shown arranged sequentially by row.
u <- matrix(c(3:14), nrow = 4, byrow = TRUE)
print(u)
# Elements will be shown arranged sequentially by column.
v <- matrix(c(3:14), nrow = 4, byrow = FALSE)
print(v)
# Define the column and row names.
rownames = c("row1", "row2", "row3", "row4")
colnames = c("column1", "colum2", "column3")
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