# Assign n Email Addresses to x Cells, Intrinsically

March 5, 2014
By

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

Assign n Email Addresses to x Cells, Intrinsically

# Assign n Email Addresses to x Cells, Intrinsically

Sample Use Case:
Marketing requests that an email address list be divided randomly into a given number of cells so that each cell would receive a different version of copy.
Below is a technique that takes n email addresses and pseudo-randomly assigns each to one of x cells. The advantage of this method is that the user does not need to maintain a log of each email address's assigned cell since the cell assignment can be reproduced at any time.

``emails <- c("[email protected]", "[email protected]", "[email protected]",     "[email protected]", "[email protected]", "[email protected]", "[email protected]",     "[email protected]", "[email protected]", "[email protected]", "[email protected]",     "[email protected]", "[email protected]", "[email protected]")length(emails)``
``## [1] 14``

Next, assign the number of cells.

``cells <- 3``

Create a vector of the number of characters in each email address.

``em.len <- nchar(emails)``

Use the modulo function (%%) to create a vector of remainders. 1 is added to the number of cells as a holdout.

``em.mod <- em.len%%(cells + 1)``

The table function summarizes how many email addresses have been assigned to each cell (including the holdout).

``table(em.mod)``
``## em.mod## 0 1 2 3 ## 3 3 4 4``

Separate the original list of email addresses into the assigned cells.

``em.1 <- emails[em.mod == 1]  #  cell 1em.2 <- emails[em.mod == 2]  #  cell 2em.3 <- emails[em.mod == 3]  #  cell 3em.0 <- emails[em.mod == 0]  #  control``

Display the email addresses assigned to each cell.

``em.1``
``## [1] "[email protected]"             "[email protected]"                ## [3] "[email protected]"``
``em.2``
``## [1] "[email protected]"     "[email protected]"## [3] "[email protected]"         "[email protected]"``
``em.3``
``## [1] "[email protected]"         "[email protected]"## [3] "[email protected]"     "[email protected]"``
``em.0``
``## [1] "[email protected]" "[email protected]"     "[email protected]"``

Now each email address has been assigned to a specific number of given cells.
Each email address will always belong to the current cell because the number of characters it has will not change.

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.