Re: Nested list data extraction bottleneck
- To: mathgroup at smc.vnet.net
- Subject: [mg107622] Re: [mg107601] Nested list data extraction bottleneck
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Fri, 19 Feb 2010 07:34:11 -0500 (EST)
- Reply-to: hanlonr at cox.net
LS = {{{0, 533}, {0, 549}, {0, 554}, {0, 547}}, {{0, 533}, {0,
536}, {0, 541}, {0, 533}}};
LS[[All, -1]][[All, -1]]
{547,533}
LS[[All, -1, -1]]
{547,533}
LS[[All, All, -1]]
{{533, 549, 554, 547},
{533, 536, 541, 533}}
#[[All, -1]] & /@ LS
{{533, 549, 554, 547},
{533, 536, 541, 533}}
Bob Hanlon
---- Mumtaz <x64x58 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 *)