Just tossing an idea up in the air - it either flies or gets shot down ! Bear with me, I'm off with flu at the moment so not thinking 100%
Could you do a cdef along the lines of : t=if (prev(t) is unknown AND d is not unknown) then t=time(d) else t=unknown. This should, if I'm switched on enough, work through the data, and set t to the timestamp of the first sample where the data is unknown. For the initial data both prev(t) and d will be unknown and so t will stay as unknown. Once the data is known, then prev(t) will cease to be unknown and no further updates will happen. That's assuming the functions required are available - I'll leave someone else to work that out. -- Simon Hobson Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed author Gladys Hobson. Novels - poetry - short stories - ideal as Christmas stocking fillers. Some available as e-books. _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
