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)

```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 *)

```

• Prev by Date: Re: Nested list data extraction bottleneck
• Next by Date: Re: Nested list data extraction bottleneck
• Previous by thread: Re: Nested list data extraction bottleneck
• Next by thread: Re: Nested list data extraction bottleneck