[R] Frequency table

[Kai Hendry]

This must be FAQ, but I can't find it in archives or with a site search.

I am trying to construct a frequency table. I guess this should be done with
table. Or perhaps factor and split. Or prop.table. cut? findInterval? Argh!

Please correct me if what I am looking for is not called a "frequency table".
Perhaps it's called grouped data.

> zz$x9
 [1] 65 70 85 65 65 65 62 55 82 59 55 66 74 55 65 56 80 73 45 64 75 58 60 56 60
[26] 65 53 63 72 80 90 95 55 70 79 62 57 65 60 47 61 53 80 75 72 87 52 72 80 85
[51] 75 70 84 60 72 70 76 70 79 72 69 80 62 74 54 58 58 69 81 84

I (think) I want it to look like:

40-49   2
50-59   15
60-69   20
70-79   19
80-89   12
90-99   2

Or the other way around with transpose.

classes = c("40-49", "50-59", "60-69", "70-79", "80-89", "90-99")
For the rownames

sum(zz$x9 > 40 & zz$x9 < 50)
For getting frequency counts is very laborious...

I got this far:
> table(cut(zz$x9, brk))

 (40,50]  (50,60]  (60,70]  (70,80]  (80,90] (90,100]
       2       19       21       19        8        1
> brk
[1]  40  50  60  70  80  90 100
> 
> t(table(cut(zz$x9, brk)))
     (40,50] (50,60] (60,70] (70,80] (80,90] (90,100]
[1,]  2      19      21      19       8       1

Still feels a million miles off.

Now I could do with a little help please after spending a couple of hours
working this out.