Re: Selecting Rows Where All Columns Satisfy a Condition

*To*: mathgroup at smc.vnet.net*Subject*: [mg82610] Re: Selecting Rows Where All Columns Satisfy a Condition*From*: samuel.blake at maths.monash.edu.au*Date*: Fri, 26 Oct 2007 05:19:19 -0400 (EDT)*References*: <ffppu6$l6g$1@smc.vnet.net>

Gregory Lypny wrote: > Hello everyone > > I've got an Nx4 numeric array called X. I'd like to pull out all > rows where -9 does not appear in any of the four columns. I know I > can this: > > Select[X, #[[1]] != -9 && #[[2]] != -9 && #[[3]] != -9 && #[[4]] != > -9 &] > > But is there a more elegant way that applies the not-equal-to > condition to each column without having to repeat it? > > Regards, > > Gregory You could use this: In[80]:= n = RandomInteger[{-10, 10}, {10, 4}] Out[80]= {{-9, 10, -2, 0}, {-1, 1, 3, 3}, {-7, -1, 0, 3}, {-5, 7, 10, -10}, {-7, 9, -8, -4}, {2, 2, -6, -6}, {5, 4, 1, 4}, {-1, -2, 7, -9}, {-8, -2, 6, 4}, {0, 6, -6, -9}} In[81]:= Select[n, FreeQ[#, -9] &] Out[81]= {{-1, 1, 3, 3}, {-7, -1, 0, 3}, {-5, 7, 10, -10}, {-7, 9, -8, -4}, {2, 2, -6, -6}, {5, 4, 1, 4}, {-8, -2, 6, 4}}