I have the following array: > head(stocks) DATE TICKER PERMNO EXCHCD TSYMBOL TRDSTAT SHROUT PRC RET
1 19950131 EWST 10001 3 EWST A 2224 -7.75000 -0.031250 2 19950228 EWST 10001 3 EWST A 2224 7.54688 -0.026210 3 19950331 EWST 10001 3 EWST A 2244 7.50000 0.00637 4 19950428 EWST 10001 3 EWST A 2244 7.50000 0.000000 5 19950531 EWST 10001 3 EWST A 2244 -7.87500 0.050000 6 19950630 EWST 10001 3 EWST A 2254 8.25000 0.060317 I am trying to find stocks(TICKER) that are delisted at points (t-5) to t(19950630) to (t+7) using the following code: #find delistings or incomplete returns for (i in 1:T) { if ( (stocks[i,1]==19950630)& (stocks[i,2]!=stocks[i5,2])|(stocks[i,2]!=stocks[i+5,2]) ) { print("Delisted stocks are: ") print(stocks[i,2]) } } But I get the following error message: Error in if ((stocks[i, 1] == 19950630) & (stocks[i, 2] != stocks[i - : argument is of length zero In addition: Warning messages: 1: In if ((stocks[i, 1] == 19950630) & (stocks[i, 2] != stocks[i - : the condition has length > 1 and only the first element will be used 2: In if ((stocks[i, 1] == 19950630) & (stocks[i, 2] != stocks[i - : the condition has length > 1 and only the first element will be used 3: In if ((stocks[i, 1] == 19950630) & (stocks[i, 2] != stocks[i - : the condition has length > 1 and only the first element will be used 4: In if ((stocks[i, 1] == 19950630) & (stocks[i, 2] != stocks[i - : the condition has length > 1 and only the first element will be used Please help?? Regards, Leigh ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.