R help - May 2002 - Did something big change in 1.5?

I can't remember the programming term -- ``implicit declaration''?
Has
this changed between 1.4.1 and 1.5? This code used to run as is:

for (i in 1:length(diff.time)) {
  if (diff.time[i] < 16) {
    total.time[i] <- ifelse(i==1, 7.5, total.time[i-1]) + diff.time[i]
    last.time[i] <- 0
  }
  else {
    total.time[i] <- 7.5
    last.time[i-1] <- 1
  }
}

Now in 1.5 I get messages saying, Object "total.time" not found. (Same
thing for last.time, as well.) However, if I include
total.time <- NA 
last.time <- NA
before this piece of code, it runs fine. Why should this be?

-- 
Stuart Luppescu -=- s-luppescu at uchicago.edu        
University of Chicago -=- CCSR 
$B:MJ8$HCRF`H~$NIc(B -=-    Kernel 2.4.18-xfs-1.1                
In Devon, Connecticut, it is unlawful to walk
 backwards after sunset. 
 

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 240 bytes
Desc: This is a digitally signed message part
Url :
https://stat.ethz.ch/pipermail/r-help/attachments/20020506/e6c68cec/attachment.bin

On 6 May 2002, Stuart Luppescu wrote:
> I can't remember the programming term -- ``implicit
declaration''? Has
> this changed between 1.4.1 and 1.5? This code used to run as is:
>
> for (i in 1:length(diff.time)) {
>   if (diff.time[i] < 16) {
>     total.time[i] <- ifelse(i==1, 7.5, total.time[i-1]) + diff.time[i]
>     last.time[i] <- 0
>   }
>   else {
>     total.time[i] <- 7.5
>     last.time[i-1] <- 1
>   }
> }
>
> Now in 1.5 I get messages saying, Object "total.time" not found.
(Same
> thing for last.time, as well.) However, if I include
> total.time <- NA
> last.time <- NA
> before this piece of code, it runs fine. Why should this be?
Because ifelse() evaluates both its arguments, and the second one isn't
defined.  You mean
  total.time[i]<-(if (i==1) 7.5 else total.time[i-1]) +diff.time[i]
or similar.

The code gives the error
Error: Object "total.time" not found
for me on R1.4.1.  Perhaps you used to have a total.time object lying
around in your workspace?

	-thomas


-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at
stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._