Re: 100 rows and 100 columns random matrix
- To: mathgroup at smc.vnet.net
- Subject: [mg123450] Re: 100 rows and 100 columns random matrix
- From: "Dr. Wolfgang Hintze" <weh at snafu.de>
- Date: Thu, 8 Dec 2011 05:21:36 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <jbniam$497$1@smc.vnet.net>
Something like this works (* set dimension of your matrix *) n = 100; (* create random matrix *) a = Array[Random[] & , {n, n}]; (* flatten out matrix to get a 1 dimensional list *) af = Flatten[a]; (* select numerical range *) Select[af, #1 < 0.5 & ]; (* calculate length of the selection, i.e. number of elements of matrix in the selection range *) Length[%] 5110 Regards, Wolfgang "Sahar Nazemi" <nazemisahar at yahoo.com> schrieb im Newsbeitrag news:jbniam$497$1 at smc.vnet.net... > Hello > I'm a student of geology who works with > Mathematica sofware .I'm learning it by myself recently. > I have a question and will appreciate if you > help me in this regard. > I have created a 100 rows and 100 columns random > matrix which its elements are between 0 to 1(for example it consists > of > 0.687,...). > Now I want to know how many of these elements > are in the range of "0 to 0.5" and how many are in the range of > "0.5 to 1". > I also use "Count" function as below > but it doesnt answer: > Count[a,{0,0.5}] > ("a" is my random matrix). > Regards > Sahar Nazemi