Course Content
R Introduction: Part I
R Introduction: Part I
Indexing
Great! You now understand how to create a vector and how to assign names to its values.
To access a specific element or elements within a vector, you can utilize indices. The index of the first element is 1, the second element is 2, and so on. To retrieve the n-th element from a vector vec, the syntax is vec[n]. Moreover, if the vector elements have assigned names, you can extract the values by their names by enclosing the name in quotes and square brackets.
Now, let’s revisit the grades example.
| Subject | Grade |
| Math | 80 |
| Physics | 75 |
| English | 95 |
| Literature | 100 |
We’ll extract the grade for Math and the grade for Literature.
It’s also possible to access multiple elements simultaneously.
Task
Continuing from the previous exercise, you have a vector named prices with each price assigned to a corresponding item name.
- Retrieve the price of
'Armchair'using its name rather than its index. - Retrieve the prices for both the
'Dining table'and'Dining chair'using their indices.
Everything was clear?
Course Content
R Introduction: Part I
R Introduction: Part I
Indexing
Great! You now understand how to create a vector and how to assign names to its values.
To access a specific element or elements within a vector, you can utilize indices. The index of the first element is 1, the second element is 2, and so on. To retrieve the n-th element from a vector vec, the syntax is vec[n]. Moreover, if the vector elements have assigned names, you can extract the values by their names by enclosing the name in quotes and square brackets.
Now, let’s revisit the grades example.
| Subject | Grade |
| Math | 80 |
| Physics | 75 |
| English | 95 |
| Literature | 100 |
We’ll extract the grade for Math and the grade for Literature.
It’s also possible to access multiple elements simultaneously.
Task
Continuing from the previous exercise, you have a vector named prices with each price assigned to a corresponding item name.
- Retrieve the price of
'Armchair'using its name rather than its index. - Retrieve the prices for both the
'Dining table'and'Dining chair'using their indices.
Everything was clear?
