[rrd-users] LAST of CDEF that converts NaN to 0 always 0

[Matthew M. Boedicker]

I have a DS x. I create a CDEF xz that is x with all NaN converted to 0. When
I use a VDEF to print the LAST of x it looks ok, but the LAST of xz is always
0. If I graph a line of xz it looks fine. Does anyone know why this is
always 0 or another way I can do this that will work?

rrdtool create test.rrd \
--start 1212566513 \
--step 3600 \
DS:x:GAUGE:7200:U:U \
RRA:AVERAGE:0.5:1:720

rrdtool update test.rrd \
1212570113:100 \
1212573713:50 \
1212577313:25 \
1212580913:75

rrdtool graph test.png \
--start 1212566513 \
DEF:x=test.rrd:x:AVERAGE \
CDEF:xz=x,UN,0,x,IF \
VDEF:xlast=x,LAST GPRINT:xlast:%lf \
VDEF:xzlast=xz,LAST GPRINT:xzlast:%lf