Re: take square of the second and third column of a table

*To*: mathgroup at smc.vnet.net*Subject*: [mg124191] Re: take square of the second and third column of a table*From*: Barrie Stokes <Barrie.Stokes at newcastle.edu.au>*Date*: Thu, 12 Jan 2012 04:20:01 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201201112220.RAA22144@smc.vnet.net>

Hi I like to use code that I think is explicit, i.e., I can see what I was doing when I read my code in 6 months time. A = {{a, b, c}, {d, e, f}, {g, h, i}, {j, k, l}} A // Column B = Table[{A[[n]][[1]], A[[n]][[2]]^2, A[[n]][[3]]^2}, {n, 1, 4}] Map[ (s \[Function] { \!\(\*SubscriptBox[\(s\), \(\(\[LeftDoubleBracket]\)\(1\)\(\ \)\(\ \[RightDoubleBracket]\)\)]\), \!\(\*SubscriptBox[\(s\), \(\(\[LeftDoubleBracket]\)\(\ \)\(2\)\(\ \)\ \(\[RightDoubleBracket]\)\)]\)^2, \!\(\*SubscriptBox[\(s\), \(\(\[LeftDoubleBracket]\)\(\ \)\(3\)\(\ \)\ \(\[RightDoubleBracket]\)\)]\)^2}), A ] Barrie PS Always a bad idea to use capitals for or as the first character of your variables; try C = 34. >>> On 12/01/2012 at 9:20 am, in message <201201112220.RAA22144 at smc.vnet.net>, hanciong awesome <hanciong at gmail.com> wrote: > Hello, suppose I have a very long table like this: > > 1 2 3 > 4 5 6 > 7 8 9 > ....... > 2 3 4 > > how can I take square of the 2nd and 3rd column? I always do it by > making a new table. so let's say the above table is A and it has 100 > lines, then I make the new table as the following: > > B=Table[{A[[n]][[1]],A[[n]][[2]]^2,A[[n]][[3]]^2},{n,1,100}] > > But if the length of the table is unknown, this way is impractical. > Could anyone suggests better way? thank you

**References**:**take square of the second and third column of a table***From:*hanciong awesome <hanciong@gmail.com>