[R] Trouble With for() Loops

[Milo Phillips-Brown]

Hello,

I'm trying to learn R (for fun!), and I've tried to find any previous 
discussion of this problem (or something like it) and haven't found one.

When I run the following command, R seems to simply stop. I get no error 
message, but I also have no ">" or "+" to type after (although I can 
type). The only solution seems to be restarting the program. Here's the 
code:

for(i in 1:150)
for(j in 1:150)
(average <-c(
(if(NO[i]==1)
{i*0}
else
{if(HA[i]==HA[j])
{while(G[j]==1)
{mean(PT[j:(i-1)])}}})))

Also, if what I'm trying to do makes any sense and someone sees an 
easier way of doing it, that would be great.

Thanks!

Milo
Undergraduate -- Reed College
Portland, OR