RE: Selecting Lists Without Null Results
- To: mathgroup at smc.vnet.net
- Subject: [mg69035] RE: [mg68970] Selecting Lists Without Null Results
- From: "David Park" <djmp at earthlink.net>
- Date: Sun, 27 Aug 2006 01:24:17 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Gregory, Use UnsameQ or =!=. Length[Select[runsTable, (#[[14]]=!= Null) &]] David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Gregory Lypny [mailto:gregory.lypny at videotron.ca] To: mathgroup at smc.vnet.net I must be doing something wrong as usual. How come I can select list with elements that have the word Null in them as a result of a computation, but I cannot exclude them? I have an array called runsTable with 179 rows, and there are five rows with Null in column 14. So, Length[Select[runsTable, #[[14]] == Null &] returns 5. But Length[Select[runsTable, (#[[14]]¬ Null) &]] returns 0 when it should return 174, that is, 179 minus 5. Am I using the NOT operator incorrectly? Regards, Gregory