PROBLEM SOLVING USING R - UNIT II - TEST 1 - MCQS

What is a matrix in R?

• A one-dimensional array

• A two-dimensional array

• A collection of data frames

• A statistical model

How can you define a matrix in R using the matrix() function?

• matrix(data)

• matrix(data, nrow)

• matrix(data, ncol)

• matrix(data, nrow, ncol)

Which argument in the matrix() function determines the direction of filling the elements?

• byrow

• bycolumn

• fill

• direction

How can you bind two matrices by rows in R?

• bind_rows()

• rbind()

• row_bind()

• merge()

What does the dim() function return in R?

• Number of rows in a matrix

• Number of columns in a matrix

• Dimensions of a matrix

• Data type of a matrix

How can you subset a specific row in a matrix in R?

• matrix[row, ]

• matrix[, row]

• matrix[row]

• matrix[row, col]

How can you extract a specific column from a matrix in R?

• matrix[row, ]

• matrix[, col]

• matrix[col]

• matrix[row, col]

How can you extract the main diagonal elements of a matrix in R?

• diag(matrix)

• main_diag(matrix)

• matrix[diag]

• matrix[main_diag]

What happens when you omit a dimension while defining a matrix in R?

• R throws an error

• R automatically assigns a value of 1 to the omitted dimension

• R automatically assigns a value of 0 to the omitted dimension

• R automatically assigns a value of NA to the omitted dimension

How can you perform matrix addition in R?

• add()

• plus()

• matrix_add()

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