Cursusinhoud
R Introduction: Part II
R Introduction: Part II
matrix() Function
Sometimes you may have only one vector that you need to convert into a matrix. How can it be done? The answer is simple - by using the matrix() function.
This function has the following parameters:
python
These are not all the parameters, but the most important for us.
data- is the vector that we want to use to build the matrix;nrow- number of rows in a new matrix;ncol- number of columns in a new matrix;byrow- logical, should the matrix be filled by rows. It's important to note that the length of the vector filled as thedataparameter must be divisible bynroworncol. If both parameters are set, thennrow*ncolmust equal the vector length.
For example, let's construct a 3x3 matrix with integers from 1 to 9.
# Vector of integers num <- 1:9 # Build a matrix from vector matrix(num, nrow = 3, ncol = 3)
As you can see, this matrix was built from above to below first. Let's set parameter byrow to T and compare the results.
num <- 1:9 # Build a matrix from vector by rows matrix(num, nrow = 3, ncol = 3, byrow = T)
As you can see, we filled this matrix from left to right. We were free to leave only one of the nrow or ncol parameters since 9 (number of elements in the vector) is divisible by 3 and returns an integer result.
Swipe to start coding
Given a vector of numbers named num.
python
Based on this vector, you need to build the following matrix.
python
Use only the matrix() function, and think about the correct values of parameters.
Oplossing
How does seq() function work? seq(a, b) generates integers from a to b inclusive. seq(a, b, c) generates integers from a to b with the step c.
Schakel over naar desktop voor praktijkervaringGa verder vanaf waar je bent met een van de onderstaande optiesBedankt voor je feedback!
matrix() Function
Sometimes you may have only one vector that you need to convert into a matrix. How can it be done? The answer is simple - by using the matrix() function.
This function has the following parameters:
python
These are not all the parameters, but the most important for us.
data- is the vector that we want to use to build the matrix;nrow- number of rows in a new matrix;ncol- number of columns in a new matrix;byrow- logical, should the matrix be filled by rows. It's important to note that the length of the vector filled as thedataparameter must be divisible bynroworncol. If both parameters are set, thennrow*ncolmust equal the vector length.
For example, let's construct a 3x3 matrix with integers from 1 to 9.
# Vector of integers num <- 1:9 # Build a matrix from vector matrix(num, nrow = 3, ncol = 3)
As you can see, this matrix was built from above to below first. Let's set parameter byrow to T and compare the results.
num <- 1:9 # Build a matrix from vector by rows matrix(num, nrow = 3, ncol = 3, byrow = T)
As you can see, we filled this matrix from left to right. We were free to leave only one of the nrow or ncol parameters since 9 (number of elements in the vector) is divisible by 3 and returns an integer result.
Swipe to start coding
Given a vector of numbers named num.
python
Based on this vector, you need to build the following matrix.
python
Use only the matrix() function, and think about the correct values of parameters.
Oplossing
How does seq() function work? seq(a, b) generates integers from a to b inclusive. seq(a, b, c) generates integers from a to b with the step c.
Schakel over naar desktop voor praktijkervaringGa verder vanaf waar je bent met een van de onderstaande optiesBedankt voor je feedback!
Schakel over naar desktop voor praktijkervaringGa verder vanaf waar je bent met een van de onderstaande opties