# Comparison Operators¶

In R we can use comparison operators to compare variables and return logical values. Let's see some relatively self-explanatory examples:

Greater Than

In [3]:

    5 > 6

Out[3]:
FALSE
In [7]:

    6 > 5

Out[7]:
TRUE

We can also do element by element comparisons for two vectors:

In [5]:

    v1 <- c(1,2,3)
    v2 <- c(10,20,30)

In [6]:

    v1 < v2

Out[6]:

1. TRUE
2. TRUE
3. TRUE

Greater Than or Equal to

In [8]:

    6 >= 6

Out[8]:
TRUE
In [10]:

    6 >= 5

Out[10]:
TRUE
In [11]:

    6 >= 7

Out[11]:
FALSE

Less Than and Less than or Equal To

In [12]:

    3 < 2

Out[12]:
FALSE
In [13]:

    2 <= 2

Out[13]:
TRUE

Be very careful with comparison operators and negative numbers! Use spacing to keep things clear. An example of a dangerous situation:

In [14]:

    var <- 1

In [15]:

    var

Out[15]:
1
In [16]:

    # Comparing var less than negative 2
    var < -2

Out[16]:
FALSE
In [17]:

    # Accidentally reassigning var!
    var <- 2

In [18]:

    var

Out[18]:
2

Keep syntax highlighting in mind to help you avoid this mistake!

Not Equal

In [19]:

    5 != 2

Out[19]:
TRUE
In [26]:

    5 != 5

Out[26]:
FALSE

Equal

In [27]:

    5 == 5

Out[27]:
TRUE
In [28]:

    2 == 3

Out[28]:
FALSE

### Vector Comparisons¶

We can apply a comparison of a single number to an entire vector, for example:

In [29]:

    v <- c(1,2,3,4,5)

In [30]:

    v < 2

Out[30]:

1. TRUE
2. FALSE
3. FALSE
4. FALSE
5. FALSE

In [31]:

    v == 3

Out[31]:

1. FALSE
2. FALSE
3. TRUE
4. FALSE
5. FALSE

Later on we will see how we can use these vector comparisons to select parts of a vector!