Re: take square of the second and third column of a table
- To: mathgroup at smc.vnet.net
- Subject: [mg124188] Re: take square of the second and third column of a table
- From: "Nasser M. Abbasi" <nma at 12000.org>
- Date: Thu, 12 Jan 2012 04:18:59 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <jel20o$lkl$1@smc.vnet.net>
- Reply-to: nma at 12000.org
On 1/11/2012 4:21 PM, hanciong awesome wrote:
>
> how can I take square of the 2nd and 3rd column?
I forgot to mention the simplest method, which is to square the slice
of the matrix directly.
tbl = {{1, 2, 3},{4, 5, 6},{7, 8, 9},{2, 3, 4}}
for second col:
tbl[[All, 2]]^2
-->{4, 25, 64, 9}
to do both cols at same time:
tbl[[All, {2, 3}]]^2
---> {{4, 9}, {25, 36}, {64, 81}, {9, 16}}
I like to Map allot, and so sometimes I overlook that it might not
be needed.
--Nasser