[R] count each answer category in each column

[David Winsemius]

On Apr 18, 2013, at 3:46 PM, Ye Lin wrote:

> Hey,
> 
> Is it possible that R can calculate each options under each column and
> return a summary table?
> 
> Suppose I have a table like this:
> 
> Gender   Age   Rate
> Female    0-10   Good
> Male        0-10   Good
> Female     11-20  Bad
> Male         11-20  Bad
> Male         >20     N/A
> 
> I want to have a summary table including the information that how many
> answers in each category, sth like this:

Some of the tables simple did not have N/A so it's not appropriate to append an N/A row for them:

 dat1<-read.table(text="
 Gender  Age  Rate
 Female    0-10  Good
 Male        0-10  Good
 Female    11-20  Bad
 Male        11-20  Bad
 Male        >20    N/A
 ",sep="",header=TRUE)

 sapply(lapply(dat1, table), as.matrix)

$Gender
       [,1]
Female    2
Male      3

$Age
      [,1]
>20      1
0-10     2
11-20    2

$Rate
     [,1]
Bad     2
Good    2
N/A     1


> 
>  X         Gender
> Male       3
> Female    2
> N/A        0
> 
>  X          Age
> 0-10         2
> 11-20         2
>> 20           1
> N/A         0
> 
> X          Rate
> Good       2
> Bad          2
> N/A         1
> 
> So basically I want to calculate, in each column, how many people choose
> each answer, including N/A. I know I can do it in Excel in a very
> visualized way, but is there anyway to do it in R in a robust way if I have
> a fairly large dataset.

You appear confused about the relative robustness of R and Excel. 

-- 

David Winsemius
Alameda, CA, USA