Re: Problem with Position
- To: mathgroup at smc.vnet.net
- Subject: [mg119644] Re: Problem with Position
- From: Leonid Shifrin <lshifr at gmail.com>
- Date: Thu, 16 Jun 2011 03:59:16 -0400 (EDT)
- References: <201106151120.HAA22862@smc.vnet.net>
Hi Dominic, This is most likely a symbolic/numerical issue. Position is based on symbolic rather than numeric comparisons. You may have success with Flatten@Position[data[[All,1]],x_/;x==0.785398] Here is one of the most recent related discussions: http://stackoverflow.com/questions/5750623/using-position-correctly Regards, Leonid On Wed, Jun 15, 2011 at 3:20 PM, Dominic W=F6rner < dominic.woerner at mpi-hd.mpg.de> wrote: > Hi, > > I have to import data from a csv file. And I get a structure > data[[rows]]={first, second,...}. > Now I want to find the rows in which, say the first entry has a specific > values. > By just looking at the data there are for example entries with value > 0.785398. > But when I try Flatten@Position[data[[All,1]],0.785398] or with > ToString[0.785398] I just get {} > > What's the problem here? > > Best, > Dominic > >
- References:
- Problem with Position
- From: Dominic Wörner <dominic.woerner@mpi-hd.mpg.de>
- Problem with Position