[daip] TIMERANG usage

[Eric Greisen]

Joseph Lazio writes:

 > Once upon a time, I learned how to structure a loop using TIMERANG:
 > Specify everything in terms of days and fill out just TIMERANG(1) and
 > TIMERANG(5).
 > 
 > Now my current conundrum:  How do I figure out the loop limits from a
 > file?
 > 
 > Specific example, suppose I have a single source file.  I'd like to
 > make images of it every 100 s.  Is there a way to set up the loop
 > automagically, using the file itself?  Something like
 > 
 > TIMERANG=0
 > GETN n
 > <extract start time>
 > <extract stop time>
 > X=(<stop time> - <start time>)/100
 > 
 > TIMERANG(1)=<start time>
 > TIMERANG(5)=TIMERANG(1)+(100/86400)
 > 
 > DO I=1, X
 >  GO IMAGR
 >  TIMERANG(1)=TIMERANG(5)
 >  TIMERANG(5)=TIMERANG(1)+(100/86400)
 > ENDDO
 > 
 > 

You could read the index table.  The verbs in aips let you read the
number of rows in the current table.  Then read the first row and last
row central times and time intervals.  The start time is T1-DT1/2
and the end time is T2+DT2/2.

GETTHEAD with "NUM ROW' will return number rows.
TABGET is used to read the table.

Even a single-source UV file can have an NX table.

daip gets a quicker answer when I am on vacation....

Eric Greisen