Indexing in Vectors
Great! Now you understand how to create a vector and assign names to its values.
To access specific elements within a vector, you can use 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, use the syntax vec[n]. Additionally, 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 in Vectors
Great! Now you understand how to create a vector and assign names to its values.
To access specific elements within a vector, you can use 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, use the syntax vec[n]. Additionally, 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?
