Question

I am trying to take the following data, and then uses this data to create a table which has the information broken down by state.

Here’s the data:

> head(mydf2, 10)
    lead_id buyer_account_id amount state
1  52055267               62    300    CA
2  52055267               64    264    CA
3  52055305               64    152    CA
4  52057682               62     75    NJ
5  52060519               62    750    OR
6  52060519               64    574    OR
15 52065951               64    152    TN
17 52066749               62    600    CO
18 52062751               64    167    OR
20 52071186               64    925    MN

I’ve allready subset the states that I’m interested in and have just the data I’m interested in:

mydf2 = subset(mydf, state %in% c("NV","AL","OR","CO","TN","SC","MN","NJ","KY","CA"))

Here’s an idea of what I’m looking for:

State     Amount       Count
NV        1              50  
NV        2              35  
NV        3              20
NV        4              15
AL        1              10 
AL        2              6
AL        3              4
AL        4              1
...

For each state, I’m trying to find a count for each amount “level.” I don’t necessary need to group the amount variable, but keep in mind that they are are not just 1,2,3, etc

> mydf$amount
   [1]  300  264  152   75  750  574  113  152  750  152  675  489  188  263  152  152  600  167   34  925  375  156  675  152  488  204  152  152
  [29]  600  489  488   75  152  152  489  222  563  215  452  152  152   75  100  113  152  150  152  150  152  452  150  152  152  225  600  620
  [57]  113  152  150  152  152  152  152  152  152  152  640  236  152  480  152  152  200  152  560  152  240  222  152  152  120  257  152  400

Is there an elegant solution for this in R for this or will I be stuck using Excel (yuck!).

Answer 1

I am not sure if I understand correctly (you have two data.frames mydf and mydf2). I’ll assume your data is in mydf. Using aggregate:

mydf$count <- 1:nrow(mydf)
aggregate(data = mydf, count ~ amount + state, length)

Is this what you are looking for?

Note: here count is a variable that is created just to get directly the output of the 3rd column as count.

Alternatives with ddply from plyr:

# no need to create a variable called count
ddply(mydf, .(state, amount), summarise, count=length(lead_id))

Here’ one could use any column that exists in one’s data instead of lead_id. Even state:

ddply(mydf, .(state, amount), summarise, count=length(state))

Or equivalently without using summarise:

ddply(mydf, .(state, amount), function(x) c(count=nrow(x)))