Beefy Boxes and Bandwidth Generously Provided by pair Networks
Problems? Is your data what you think it is?
 
PerlMonks  

Re^2: Splicing Arrays on pre-defined indices

by harishnuti (Beadle)
on Jun 28, 2008 at 02:31 UTC ( #694482=note: print w/replies, xml ) Need Help??


in reply to Re: Splicing Arrays on pre-defined indices
in thread Splicing Arrays on pre-defined indices

Thanks a lot for it.. but indeed the above is otherway meaning we are considering indices on what we want rather exclusion , but my requirement is we should exclude certain col by specifying indices( for ex: here @incides)..
my $line = "1!2!3!4!5!6!7!8!9"; # Original line read my @arr = split /!/, $line; my @indices = (2,5..8); #i need these indices to be sliced print join(" : ", @arr);#original splice (@arr,@indices,1); # something like this iam trying to achieve print "\n"; # i might be having 30 to 40 col of which i dont need 4 to 5, so its b +etter i slice 4 to 5 col's instead of considering 30 col's

Replies are listed 'Best First'.
Re^3: Splicing Arrays on pre-defined indices
by ikegami (Pope) on Jun 28, 2008 at 14:29 UTC
    my @exclude = (2,5..8); my @exclude_lkup; $exclude_lkup[$_] = 1 for @exclude; my $line = "1!2!3!4!5!6!7!8!9"; my @arr = split /!/, $line; my @filtered = map $arr[$_], grep !$exclude_lkup[$_], 0..$#arr; print("@filtered\n"); # 1 2 4 5
      This is awesome, this is what iam looking for....Thx a lot.
      Since I just updated my previous suggestion I figured I would Benchmark things...
      Not that it matters but I thought you might be interested.
      Update There was an issue with how I ran the test before. Here are the updated code and results.
      #!/usr/bin/perl -w use strict; use Benchmark; my $count = 500000; my $line = "1!2!3!4!5!6!7!8!9"; my @arr = split /!/, $line; my @exclude = (2,5..8); my @exclude_lkup; $exclude_lkup[$_] = 1 for @exclude; sub ikegami { my @tarr = @arr; my @filtered = map $tarr[$_], grep !$exclude_lkup[$_], 0..$#tarr; } sub injun { my @tarr = @arr; @tarr[@exclude] = (); @tarr = grep $_, @tarr; } timethese ( $count, {'Ikegami' => '&ikegami', 'InjunJoel' => '&injun'} );
      Results in
      Benchmark: timing 500000 iterations of Ikegami, InjunJoel... Ikegami: 16 wallclock secs (15.88 usr + 0.00 sys = 15.88 CPU) @ 314 +94.08/s (n=500000) InjunJoel: 10 wallclock secs ( 11.05 usr + 0.00 sys = 11.05 CPU) @ 4 +5265.25/s (n=500000)
      Though I'm not versed enough in O(n) notation to tell you why...

      -InjunJoel
      "I do not feel obliged to believe that the same God who endowed us with sense, reason and intellect has intended us to forego their use." -Galileo

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://694482]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others lurking in the Monastery: (4)
As of 2020-10-31 08:21 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    My favourite web site is:












    Results (287 votes). Check out past polls.

    Notices?