# Example 7.1: Create a Fibonacci sequence

[This article was first published on

Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.

**SAS and R**, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.

The Fibonacci numbers have many mathematical relationships and have been discovered repeatedly in nature. They are constructed as the sum of the previous two values, initialized with the values 1 and 1.

A pdf of this example is available here.

**SAS**

In SAS, we use the `lag` function (section 1.4.17, p. 22) to retrieve the last value.

data fibo; do i = 1 to 10; fib = sum(fib, lag(fib)); if i eq 1 then fib = 1; output; end; run; proc print data=fibo; run;

This generates the following output:

Obs i fib 1 1 1 2 2 1 3 3 2 4 4 3 5 5 5 6 6 8 7 7 13 8 8 21 9 9 34 10 10 55

**R**

In R we can loop over an array to perform the same job.

len

This generates the following output:

> fibvals [1] 1 1 2 3 5 8 13 21 34 55

To

**leave a comment**for the author, please follow the link and comment on their blog:**SAS and R**.R-bloggers.com offers

**daily e-mail updates**about R news and tutorials about learning R and many other topics. Click here if you're looking to post or find an R/data-science job.

Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.