render_graph_main ()
{
   last_x="$1"
   png_file="img/wrap-$last_x.png"
   /usr/bin/rrdtool graph /srv/www/$png_file -a PNG --lazy -i \
   -t "Wrap CPU Temperature in C" \
   -w 600 \
   --end now --start end-${last_x} \
   DEF:cpu=$rrd_dbpath/wrap/sensors-lm77-i2c-0-48/temperature-temp1.rrd:value:AVERAGE \
   VDEF:cpu_max=cpu,MAXIMUM \
   VDEF:cpu_avg=cpu,AVERAGE \
   VDEF:cpu_min=cpu,MINIMUM \
   VDEF:cpu_last=cpu,LAST \
   COMMENT:"\t\t\g" \
   COMMENT:"Maximum\t\t\g" \
   COMMENT:"Average\t\t\g" \
   COMMENT:"Minimum\t\t\g" \
   COMMENT:"Last\l" \
   LINE1:cpu#FF0000:"CPU\t\t\g" \
   GPRINT:cpu_max:"%.1lf\t\t\g" \
   GPRINT:cpu_avg:"%.1lf\t\t\g" \
   GPRINT:cpu_min:"%.1lf\t\t\g" \
   GPRINT:cpu_last:"%.1lf\l" \
   > /dev/null
   echo "<img src=/$png_file>"
}