Raymond Vermeer wrote: > does anyone no how to do the following ? > I have a rrdfile with 3 GAUGE datasources A, B and C. > Now I want to graph the following formula on a line or area : > > (A + B - C) / (A + B)
I'll give it a try but first I want to ask you something: Did you read the tutorial on RPN ? If yes: what was difficult to understand ? Anyway, divide the problem in smaller portions: x1 = (A+B-C) x2 = (A+B) result = x1 / x2 divide x1 further: xx1 = A + B result = xx1 - C Paste everything into RPN: A,B,+,C,-,A,B,+,/ Sanity check, by following the same rules as RRDtool does: Complete line: CDEF:result=A,B,+,C,-,A,B,+,/ stack after first calculation (A+B),C,-,A,B,+,/ stack after second calculation (A+B-C),A,B,+,/ stack after third calculation (A+B-C),(A+B),/ stack after fourth calculation (A+B-C)/(A+B) I didn't exactly test it but I don't think I made a mistake. Anyway, use at own risk (as always by the way). HTH -- __________________________________________________________________ / [EMAIL PROTECTED] [EMAIL PROTECTED] \ | work private | | My employer is capable of speaking therefore I speak only for myself | +----------------------------------------------------------------------+ | Technical questions sent directly to me will be nuked. Use the list. | +----------------------------------------------------------------------+ | http://faq.mrtg.org/ | | http://rrdtool.eu.org --> tutorial | +----------------------------------------------------------------------+ -- Unsubscribe mailto:[EMAIL PROTECTED] Help mailto:[EMAIL PROTECTED] Archive http://www.ee.ethz.ch/~slist/rrd-users WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi
