Thanks so much for this.   Only one question reamined to be clear. After each reshuffling I have to pick certain observation. For example at the each sample I have to pick 2, 4, 56, 485, 364 and 102th observation in the first reshuffling. And 321, 784, 34, 721, 57 and 1089th observation at the second reshuffling and so on.   Regards,   Oslo ________________________________ From: "Data _null_;" <iebupdte@GMAIL.COM> To: SAS-L@LISTSERV.UGA.EDU Sent: Tue, March 8, 2011 11:54:19 AM Subject: Re: reshuffle and pick data This? data test;   infile cards dsd;   input Y x1-x9;   cards; 1.67162948,0,1,1,1,1,0,1,1 -0.25270276,1,1,1,1,1,0,1,1 0.341815127,1,1,1,1,1,0,1,1 0.785439489,0,1,1,1,1,0,1,1 0.998317613,0,1,1,1,1,0,1,1 2.336096876,1,1,1,1,1,0,1,1 0.617410817,1,1,1,1,1,0,1,1 0.647218152,1,1,0,1,1,0,0,1 -0.967639024,0,1,0,1,1,0,1,1 -1.050822664,0,0,0,1,1,0,1,1 1.685767604,0,1,0,0,0,0,1,1 0.89101935,1,1,0,1,1,0,1,1 1.17418089,0,1,0,1,1,1,1,0 ;;;;;   run; proc surveyselect rep=50 n=5 out=samples;   run; proc print;   run; On Tue, Mar 8, 2011 at 11:35 AM, oslo <hokut1@yahoo.com> wrote: > Dear SAS-L Usere; > > Assume that I have a data set as follow. I want pick certain observations > (say 4, 6, 8, 10 and 12th observations in data set) each time after reshuffling > data set. Data set is big one and I need do this 50 times. Any help would be > greatly appreciated. > > > Regards, > > Oslo > > > obs Y x1 x2 x3 x4 x5 x6 x7 x8    x9 > 1  1.67162948 0 1 1 1 1 0 1 1 > 2  -0.25270276 1 1 1 1 1 0 1 1 > 3  0.341815127 1 1 1 1 1 0 1 1 > 4  0.785439489 0 1 1 1 1 0 1 1 > 5  0.998317613 0 1 1 1 1 0 1 1 > 6  2.336096876 1 1 1 1 1 0 1 1 > 7  0.617410817 1 1 1 1 1 0 1 1 > 8  0.647218152 1 1 0 1 1 0 0 1 > 9  -0.967639024 0 1 0 1 1 0 1 1 > 10  -1.050822664 0 0 0 1 1 0 1 1 > 11  1.685767604 0 1 0 0 0 0 1 1 > 12  0.89101935 1 1 0 1 1 0 1 1 > 13  1.17418089 0 1 0 1 1 1 1 0 > > > > >