From c9d10bf081a5a4bb0d46117c94311e5c010fd2ef Mon Sep 17 00:00:00 2001 From: oetiker Date: Sat, 15 Jan 2011 13:01:13 +0000 Subject: [PATCH] added explanation on the rows returned from fetch. fix for #291. git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk/program@2170 a5681a0c-68f1-0310-ab6d-d61299d08faa --- doc/rrdtutorial.pod | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/doc/rrdtutorial.pod b/doc/rrdtutorial.pod index f5ab0f3..e29cd50 100644 --- a/doc/rrdtutorial.pod +++ b/doc/rrdtutorial.pod @@ -323,13 +323,18 @@ It should return the following output: 920808600: 6.6666666667e-03 920808900: 3.3333333333e-03 920809200: nan - -If it doesn't, something may be wrong. Perhaps your OS will print -"NaN" in a different form. "NaN" stands for "Not A Number". If your OS -writes "U" or "UNKN" or something similar that's okay. If something -else is wrong, it will probably be due to an error you made (assuming -that my tutorial is correct of course :-). In that case: delete the -database and try again. + 920809500: nan + +Note that you might get more rows than you expect. The reason for this is +that you ask for a time range that ends on 920809200. The number that is +written behind 920809200: in the list above covers the time range from +920808900 to 920809200, EXCLUDING 920809200. Hence to be on the sure side, +you receive the entry from 920809200 to 920809500 as well since it INCLUDES +920809200. You may also see "NaN" instead of "nan" this is OS dependent. +"NaN" stands for "Not A Number". If your OS writes "U" or "UNKN" or +something similar that's okay. If something else is wrong, it will probably +be due to an error you made (assuming that my tutorial is correct of course +:-). In that case: delete the database and try again. The meaning of the above output will become clear below. -- 2.30.2