[rrd-users] Temperature diff colors

[Simon Hobson]

Martin <martin at swetech.se> wrote:

> I´m wondering if anyone has a code example for showing diffrent colors in a graph depending on temperatue like this, if it above +0 and up the color is red and if its below -0 its blue ?

Here's one I did that does "light red" when things are close to the limit, and "full on red" when above the limit (it's part of a Bash script) :

>   echo "${RRDHead}
> 
>         DEF:op_pc_ave=${RRDPath}/${RRDName}:op_pc:AVERAGE
>         DEF:op_pc_min=${RRDPath}/${RRDName}:op_pc:MIN
>         DEF:op_pc_max=${RRDPath}/${RRDName}:op_pc:MAX
>         CDEF:op_pc_spread=op_pc_max,op_pc_min,-
>         VDEF:v_op_pc_ave=op_pc_ave,AVERAGE
>         VDEF:v_op_pc_max=op_pc_max,MAXIMUM
>         VDEF:v_op_pc_min=op_pc_min,MINIMUM
>         VDEF:v_op_pc_lst=op_pc_ave,LAST
> 
>         CDEF:alarm1=op_pc_max,${Plimit},100,LIMIT
>         AREA:alarm1#FFBFBF:
>         CDEF:alarm2=op_pc_max,99,10000,LIMIT
>         AREA:alarm2#FF0000:
> 
>         COMMENT:\"                  min      ave      max      last\n\"
>         HRULE:${Plimit}#7F0000
>         AREA:op_pc_min#FFFFFF00:
>         AREA:op_pc_spread#BFBFFF::STACK
>         LINE1:op_pc_ave#0000FF:\"%age Power\"
>         GPRINT:v_op_pc_min:\"%6.0lf \"
>         GPRINT:v_op_pc_ave:\"%6.0lf \"
>         GPRINT:v_op_pc_max:\"%6.0lf \"
>         GPRINT:v_op_pc_lst:\"%6.0lf\"
> 
> 
>         COMMENT:\"  Data to ${PrintedTime}\n\"
>         >

For yours' what I'd suggest is two CDEFs, one which is X when X < 0 and UNKN when X >= 0, the other which is X when X is >= 0 and UNKN when X < 0. Then plot the first CDEF in blue, and the second one in red.

So something like :
CDEF:xb=x,unkn,x,0,lt,if
CDEF:xr=x,unkn,x,0,ge,if
should (if I've got my RPN right from memory) give you the two series to draw.