Missing Values In R

Kevin Feasel

2016-07-20

R

David Smith explains NA values in R:

Here’s a little puzzle that might shed some light on some apparently confusing behaviour by missing values (NAs) in R:

What is NA^0 in R?

You can get the answer easily by typing at the R command line:

> NA^0
[1] 1

But the interesting question that arises is: why is it 1? Most people might expect that the answer would be NA, like most expressions that include NA. But here’s the trick to understanding this outcome: think of NA not as a number, but as a placeholder for a number that exists, but whose value we don’t know.

Definitely read the comments on this one.

Related Posts

Building An Image Recognizer With R

David Smith has a post showing how to build an image recognizer with R and Microsoft’s Cognitive Services Library: The process of training an image recognition system requires LOTS of images — millions and millions of them. The process involves feeding those images into a deep neural network, and during that process the network generates […]

Read More

Checkpointing Code For Reproduction

David Smith tells an interesting story about a reproducibility problem with data analysis: Timo Grossenbacher, data journalist with Swiss Radio and TV in Zurich, had a bit of a surprise when he attempted to recreate the results of one of the R Markdown scripts published by SRF Data to accompany their data journalism story about vested interests of Swiss […]

Read More

Categories

July 2016
MTWTFSS
« Jun Aug »
 123
45678910
11121314151617
18192021222324
25262728293031