Re: your mail

[Ben Pfaff]

On Mon, Jun 12, 2017 at 11:11:10AM -0700, Braxton Alfred wrote:
> I am trying to do some analyses on medical lab tests which occur at varying
> times.  I need to have the number of days between tests.  DATEDIFF, while
> described in the manual, does not work, but even if it did I need to be able
> to reference 'date(i) - date(i-k)'.  I created a variable 'julian' (the
> number of days since 1500 or so) using XDATE.TDAY(date) but cannot VECTORize
> it.  
> 
> This is holding up the whole project and people stop talking and look at me
> strangely when I come near. 

When you say "DATEDIFF does not work", what do you mean?  If you can
explain why it doesn't work, then perhaps we can help.  In particular,
if there is a bug in DATEDIFF, then I would like to fix it.

When you say that you cannot put your variable into a vector, what do
you mean?  If there's a problem with the VECTOR implementation, then I
would like to fix that too.