Take Notes
Add notes here about the concepts you've learned and code cells with code you want to keep.
작동 방식
오른쪽 편집기에는 연습 문제를 해결하기 위해 R 코드를 입력해야 합니다. '답변 제출' 버튼을 누르면, 각 코드 줄이 R에 의해 해석되고 실행되며, 코드가 올바른지 여부에 대한 메시지를 받게 됩니다. R 코드의 출력은 오른쪽 하단 콘솔에 표시됩니다.
R은 주석을 추가하기 위해 #
기호를 사용합니다. 이렇게 하면 여러분과 다른 사람들이 R 코드의 내용을 이해할 수 있습니다. 마치 트위터처럼 말이죠! 주석은 R 코드로 실행되지 않으므로 결과에 영향을 주지 않습니다. 예를 들어, 오른쪽 편집기에서 3 + 4 계산은 주석입니다.
또한 콘솔에서 직접 R 명령을 실행할 수도 있습니다. 이는 R 코드를 실험하는 좋은 방법입니다. 왜냐하면 제출한 내용이 올바른지 확인되지 않기 때문이죠.
Add your notes here
# Add your code snippets here
# Calculate 3 + 4
3 + 4
# Calculate 6 + 12
6 + 12
Arithmetic with R
In its most basic form, R can be used as a simple calculator. Consider the following arithmetic operators:
- Addition:
+
- Subtraction:
-
- Multiplication:
*
- Division:
/
- Exponentiation:
^
- Modulo:
%%
The last two might need some explaining:
- The
^
operator raises the number to its left to the power of the number to its right: for example3^2
is 9. - The modulo returns the remainder of the division of the number to the left by the number on its right, for example 5 modulo 3 or
5 %% 3
is 2.
With this knowledge, follow the instructions to complete the exercise.
7%%4
# An addition
5 + 5
# A subtraction
5 - 5
# A multiplication
3 * 5
# A division
(5 + 5) / 2
# Exponentiation
3^3
# Modulo
7%%4
Variable assignment
A basic concept in (statistical) programming is called a variable.
A variable allows you to store a value (e.g. 4) or an object (e.g. a function description) in R. You can then later use this variable's name to easily access the value or the object that is stored within this variable.
You can assign a value 4 to a variable my_var
with the command
my_var <- 4
# Assign the value 42 to x
x <- 56
# Print out the value of the variable x
x
Variable assignment (2)
Suppose you have a fruit basket with five apples. As a data analyst in training, you want to store the number of apples in a variable with the name my_apples
.
# Assign the value 5 to the variable my_apples
my_apples <- 5
# Print out the value of the variable my_apples
my_apples
Variable assignment (3)
Every tasty fruit basket needs oranges, so you decide to add six oranges. As a data analyst, your reflex is to immediately create the variable my_oranges
and assign the value 6 to it. Next, you want to calculate how many pieces of fruit you have in total. Since you have given meaningful names to these values, you can now code this in a clear way:
my_apples + my_oranges
# Assign a value to the variables my_apples and my_oranges
my_apples <- 5
# Add these two variables together
my_oranges <- 3
# Create the variable my_fruit
my_fruit <- my_apples + my_oranges
minus_furit <- my_apples - my_oranges
mul_fruit <- my_apples * my_oranges
div_fruit <- my_apples / my_oranges
my_fruit
minus_furit
mul_fruit
div_fruit
Apples and oranges
Common knowledge tells you not to add apples and oranges. But hey, that is what you just did, no :-)? The my_apples
and my_oranges
variables both contained a number in the previous exercise. The +
operator works with numeric variables in R. If you really tried to add "apples" and "oranges", and assigned a text value to the variable my_oranges
(see the editor), you would be trying to assign the addition of a numeric and a character variable to the variable my_fruit
. This is not possible.
룰렛의 승리/패배를 변수 roulette_vector
에 할당하세요. $24를 잃은 후에 $50을 잃었으며, $100을 얻었고, $350을 잃었으며, $10을 얻었습니다.