[Rrd-announce] Drawing daily Min/Max graph from a source with UN values

[Alexander Topolanek]

Hello all,

I'm fetching data from my radio weather station and put them into 
graphs. A graph that shows the temperature over the day, and follow up 
graphs that show min, max and average temps from the previous days.

Unfortunately some times the transmission from the weather station 
fails, and I have unknown values for a few minutes. A short gap in the 
daily temps gauge is not a problem, but for any day with a UN Value I do 
not get min/max/average calculations...


That is the command for calculation the weekly values:

rrdtool graph temps-week-2103.png   -s 'now - 1 week' -e 'now'  \
--title "Temperatur in LE " \
DEF:temps9=/var/rrd/weather.rrd:temps9:AVERAGE  \
VDEF:temps9min=temps9,MINIMUM \
VDEF:temps9max=temps9,MAXIMUM \
VDEF:temps9last=temps9,LAST \
COMMENT:"\t\t\tMin  " \
COMMENT:"Max  " \
COMMENT:"Aktuell" \
COMMENT:"\n" \
LINE4:temps9#00C000:"KS-300     " \
GPRINT:temps9min:"%6.1lf " \
GPRINT:temps9max:"%6.1lf %S" \
GPRINT:temps9last:"%6.1lf %S \n"

I've tried to play around with CDEF

rrdtool graph temps-week-2103.png   -s 'now - 1 week' -e 'now'  \
--title "Temperatur in LE " \
DEF:temps9=/var/rrd/weather.rrd:temps9:AVERAGE  \
VDEF:temps9last=temps9,LAST  \
CDEF:temps9c=temps9,UN,temps9last,temps9,IF \
VDEF:temps9min=temps9c,MINIMUM \
VDEF:temps9max=temps9c,MAXIMUM \
VDEF:temps9last=temps9,LAST \
COMMENT:"\t\t\tMin  " \
COMMENT:"Max  " \
COMMENT:"Aktuell" \
COMMENT:"\n" \
LINE4:temps9#00C000:"KS-300     " \
GPRINT:temps9min:"%6.1lf " \
GPRINT:temps9max:"%6.1lf %S" \
GPRINT:temps9last:"%6.1lf %S \n" \

but that gives an ERROR: Attempting to reuse 'temps9last'

any help?

thanks and kind regards,
Alexander