Re: Nested list data extraction bottleneck
- To: mathgroup at smc.vnet.net
- Subject: [mg107618] Re: Nested list data extraction bottleneck
- From: Ray Koopman <koopman at sfu.ca>
- Date: Fri, 19 Feb 2010 07:33:26 -0500 (EST)
- References: <hllidp$q6$1@smc.vnet.net>
On Feb 19, 12:34 am, Mumtaz <x64... at gmail.com> wrote:
> (* BEGIN the beguine simple code *)
>
> ClearAll["Global`*"]
>
> (* prototype data list *)
> LS = {{{0,533},{0,549},{0,554},{0,547}},{{0,533},{0,536},{0,541},
> {0,533}}};
>
> (* list LS dimensions *)
> LSdim = Dimensions[LS]
> {2,4,2}
>
> (* list LS terminal values -- major bottle neck for higher dimensions
> *)
> LSterminal = Table[Last[LS[[i]]], {i, LSdim[[3]]}]
> {{0,547},{0,533}}
>
> (* extract relevant list LS terminal values data *)
> LSterminal[[All,2]]
> {547,533}
>
> (* OK *)
> (* END simple code *)
>
> (* No doubt, there is a better way to extract terminal values from
> list LS since the data has already been generated; Table function for
> generating LSterminal should not be necessary *)
>
> (* Any ideas appreciated *)
>
> (* Further, any ideas on extracting the following type stream from
> list LS would also be appreciated: *)
> (* SomeFunction[LS] operating on LS above will output: *)
> (* {{533, 549, 554, 547}, {533, 536, 541, 533}} *)
>
> (* Thanks in advance and best regards, M *)
>
> (* PS Please note the 0 element in list LS is a result of rounding for
> legibility. Parsing the list LS on that basis would not be optimal.
> All numbers are Real *)
Transpose[LS,{2,3,1}][[2]]
{{533,549,554,547},{533,536,541,533}}