[R] help with splitting parts of data frame

[Charles Berry]

Andras Farkas <motyocska <at> yahoo.com> writes:

> 
> Dear All,
> 
> please help with the following if you can:
> 
[snip details]
> 
> ####
> first24 <-sum(unlist(c(subset(df, df[, 'simt'] > 0 & df[, 'simt'] <= 
> z[1], 3))))
> second24 <-sum(unlist(c(subset(df, df[, 'simt'] > z[1] & df[, 'simt'] <= 
> z[2], 3))))
> third24 <-sum(unlist(c(subset(df, df[, 'simt'] > z[2] & df[, 'simt'] <= 
> z[3], 3))))
> fourth24 <-sum(unlist(c(subset(df, df[, 'simt'] > z[3] & df[, 'simt'] <= 
> z[4], 3))))
> fifth24 <-sum(unlist(c(subset(df, df[, 'simt'] > z[4] & df[, 'simt'] <=
z[5], 3))))
> sixth24 <-sum(unlist(c(subset(df, df[, 'simt'] > z[5] & df[, 'simt'] <= 
> z[6], 3))))
> 
> last24 <-sum(unlist(c(subset(df, df[, 'simt'] > z[6] , 3))))
> 
> my end result is to get this vector:
> 
> c(first24,second24,third24,fourth24,fifth24,sixth24,last24)
> 
> ####
> 

Some hints:

see 

   ?xtabs 

for weighted tabulations and 

   ?cut

for forming categories to tabulate. 

Try to solve this using just those functions, 'c', and the '~' operator.

It can be done in one line.

HTH,

Chuck