R numbers from 1 to 100 [duplicate]

Question

Possible Duplicate:
How to generate a vector containing a numeric sequence?

In R, how can I get the list of numbers from 1 to 100? Other languages have a function 'range' to do this. R's range does something else entirely.

> range(1,100) [1]   1 100 

Answer 1

Your mistake is looking for range, which gives you the range of a vector, for example:

range(c(10, -5, 100)) 

gives

 -5 100 

Instead, look at the : operator to give sequences (with a step size of one):

1:100 

or you can use the seq function to have a bit more control. For example,

##Step size of 2 seq(1, 100, by=2) 

or

##length.out: desired length of the sequence seq(1, 100, length.out=5) 

Answer 2

If you need the construct for a quick example to play with, use the : operator.

But if you are creating a vector/range of numbers dynamically, then use seq() instead.

Let's say you are creating the vector/range of numbers from a to b with a:b, and you expect it to be an increasing series. Then, if b is evaluated to be less than a, you will get a decreasing sequence but you will never be notified about it, and your program will continue to execute with the wrong kind of input.

In this case, if you use seq(), you can set the sign of the by argument to match the direction of your sequence, and an error will be raised if they do not match. For example,

seq(a, b, -1) 

will raise an error for a=2, b=6, because the coder expected a decreasing sequence.