Hands-On Data Science with Anaconda

Dealing with missing data

First, let's look at the missing codes for different languages:

Languages	Missing code	Explanation or examples
R	NA	NA stands for Not Available
Python	nan	import scipy as sp misingCode=sp.nan
Jullia	missing	julia> missing + 5 missing
Octave	NaN	Same for MATLAB as well

Table 3.7: Missing codes for R, Python, Julia, and Octave

For R, the missing code is NA. Here are several functions we could use to remove those missing observations, shown in an example:

> head(na_example,20) 
[1]  2  1  3  2  1  3  1  4  3  2  2 NA  2  2  1  4 NA  1  1  2 
> length(na_example) 
[1] 1000 
> x<-na.exclude(na_example) 
> length(x) 
[1] 855 
> head(x,20) 
[1] 2 1 3 2 1 3 1 4 3 2 2 2 2 1 4 1 1 2 1 2 

In the previous ...