The steps taken to fix an R problem.
To prepare for the Portfolio Probe blog post called “Implied alpha and minimum variance”, I tried to update a matrix of daily stock prices using a function I had written for the purpose.
When I tried to do what I wanted, I got:
> univclose130518 <- pp.updateclose(jjuc[,1:5]) done with: MMM ABT ANF ACE ACN Error in if (beg > end) stop("Start date must be before end date.") : missing value where TRUE/FALSE needed