RE: sort with special order
How about this? Jo
#!/usr/bin/perl
use strict;
use warnings;
my @list = qw/dog is a there/;
my @sortOrder = (3,1,2,0);
my @sorted;
foreach (@sortOrder) { push(@sorted,$list[$_]); }
print @sorted;
exit;
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Re: sort with special order
Jo for lists and groups wrote:
How about this? Jo
#!/usr/bin/perl
use strict;
use warnings;
my @list = qw/dog is a there/;
my @sortOrder = (3,1,2,0);
my @sorted;
foreach (@sortOrder) { push(@sorted,$list[$_]); }
print @sorted;
exit;
...or this:
#!/usr/bin/perl
use strict;
use warnings;
my @list = map { qw(dog is a there)[$_]; } qw(3 1 2 0);
print @list;
... or all at once:
print join(' ', my @list = map { qw(dog is a there)[$_]; } qw(3 1 2 0));
:) Steve
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Re: sort with special order
Steve Bertrand wrote:
Jo for lists and groups wrote:
How about this? Jo
#!/usr/bin/perl
use strict;
use warnings;
my @list = qw/dog is a there/;
my @sortOrder = (3,1,2,0);
my @sorted;
foreach (@sortOrder) { push(@sorted,$list[$_]); }
print @sorted;
exit;
...or this:
#!/usr/bin/perl
use strict;
use warnings;
my @list = map { qw(dog is a there)[$_]; } qw(3 1 2 0);
print @list;
Of course, it would likely be required to have the data in arrays first,
so this is likely more feasible:
my @list = qw (dog is a there);
my @order = qw (3 1 2 0);
@list = map { $list[$_]; } @order;
print @list;
smime.p7s
Description: S/MIME Cryptographic Signature
Re: sort with special order
On Fri, Jul 24, 2009 at 11:01, Jo for lists and
groupsourli...@rogers.com wrote:
How about this? Jo
#!/usr/bin/perl
use strict;
use warnings;
my @list = qw/dog is a there/;
my @sortOrder = (3,1,2,0);
my @sorted;
foreach (@sortOrder) { push(@sorted,$list[$_]); }
print @sorted;
exit;
snip
What do you do when the list is qw/there a dog is/? Your code does
not sort the data. I guess you could go insane and write something
like:
my %position = (
there = 0,
is= 1,
a = 2,
dog = 3,
);
for my $word (@list) {
$sorted[$position{$word}] = $word;
}
But that would only work if the list will only contain one item each
of there, is, a, or dog. The sort is not only more flexible,
it is faster (due to the low number of items to be sorted and the fact
that sort is implemented in C):
positional_hash = there is a dog
sort = there is a dog
positional_array = there is a dog
Rate positional_hash positional_array sort
positional_hash 253734/s -- -11% -15%
positional_array 284350/s 12% -- -5%
sort 297890/s 17% 5% --
#!/usr/bin/perl
use strict;
use warnings;
use List::Util qw/maxstr/;
use Benchmark;
my %position = (
there = 0,
is= 1,
a = 2,
dog = 3,
);
my @sortOrder = (3,1,2,0);
my @a = qw/dog is a there/;
my %subs = (
sort = sub {
return join , sort { $position{$a} = $position{$b} } @a;
},
positional_array = sub {
my @sorted;
push @sorted, $a[$_] for @sortOrder;
return join , @sorted;
},
positional_hash = sub {
my @sorted;
$sorted[$position{$_}] = $_ for @a;
return join , @sorted;
},
);
for my $sub (keys %subs) {
print $sub = , $subs{$sub}-(), \n;
}
Benchmark::cmpthese -1, \%subs;
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Re: sort with special order
On Fri, Jul 24, 2009 at 00:14, sys admsys...@computermail.net wrote:
Hi,
When I got a word list, I want it to be sorted with special order.
for example, I got this array:
(dog,is,a,there);
I want the sorted result is:
(there,is,a,dog);
How to code it? Thank you.
snip
You need to some way to map the list to be sorted into something that
can be sorted. When you hear the phrase map X into Y, you should
think of a hash:
#!/usr/bin/perl
use strict;
use warnings;
my %sort_order = (
there = 1,
is= 2,
a = 3,
dog = 4,
);
my @list = qw/dog is a there/;
my @sorted = sort { $sort_order{$a} = $sort_order{$b} } @list;
print list:\n, (map { \t$_\n } @list),
sorted\n, map { \t$_\n } @sorted;
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Re: sort with special order
On Oct 3, 2005, at 17:35, JupiterHost.Net wrote:
I need to sort them so they are in order of Q, B , then Z
The real array will have between 1 to 100 items, just FYI
They all go in ASCII relative order except B - Q, thus a way to get
it is to handle that special case and delegate to cmp the rest:
my @sorted = sort {
my $x = substr($a, 0, 1) . substr($b, 0, 1);
$x eq BQ || $x eq QB ? $b cmp $a : $a cmp $b;
} @array;
I used the concatenation for clarity, you see the idea anyway if
that's too expensive for your usage.
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Re: sort with special order
On Oct 3, JupiterHost.Net said:
I have a list of strings that start with an uppercase B, Q, or Z
I need to sort them so they are in order of Q, B , then Z
Any ideas or input on how to efficiently do that with sort() or even map() is
most appreciated :) perldoc -f sort|-f map didn't appear to address this
situation :(
I would use map() before and after sort() to correct leading characters.
my @sorted =
map { tr/123/QBZ/; $_ }
sort
map { tr/QBZ/123/; $_ }
@data;
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Re: [SPAM DETECT] Re: sort with special order
On Oct 3, 2005, at 18:16, Jeff 'japhy' Pinyan wrote:
On Oct 3, JupiterHost.Net said:
I have a list of strings that start with an uppercase B, Q, or Z
I need to sort them so they are in order of Q, B , then Z
Any ideas or input on how to efficiently do that with sort() or
even map() is most appreciated :) perldoc -f sort|-f map didn't
appear to address this situation :(
I would use map() before and after sort() to correct leading
characters.
my @sorted =
map { tr/123/QBZ/; $_ }
sort
map { tr/QBZ/123/; $_ }
@data;
There's a potential gotcha there: since all Qs and Bs are being
swapped lexicographic order after the first character is also
changed. That might not be an issue though.
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Re: sort with special order
On Oct 3, JupiterHost.Net said:
I have a list of strings that start with an uppercase B, Q, or Z
I need to sort them so they are in order of Q, B , then Z
Any ideas or input on how to efficiently do that with sort() or even
map() is most appreciated :) perldoc -f sort|-f map didn't appear to
address this situation :(
Jeff 'japhy' Pinyan wrote:
I would use map() before and after sort() to correct leading characters.
my @sorted =
map { tr/123/QBZ/; $_ }
sort
map { tr/QBZ/123/; $_ }
@data;
Xavier Noria wrote:
They all go in ASCII relative order except B - Q, thus a way to get
it is to handle that special case and delegate to cmp the rest:
my @sorted = sort {
my $x = substr($a, 0, 1) . substr($b, 0, 1);
$x eq BQ || $x eq QB ? $b cmp $a : $a cmp $b;
} @array;
I used the concatenation for clarity, you see the idea anyway if that's
too expensive for your usage.
Brilliant! I'll benchmark those ideas :) Thanks you two!
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Re: [SPAM DETECT] Re: sort with special order
On Oct 3, Xavier Noria said:
On Oct 3, 2005, at 18:16, Jeff 'japhy' Pinyan wrote:
my @sorted =
map { tr/123/QBZ/; $_ }
sort
map { tr/QBZ/123/; $_ }
@data;
There's a potential gotcha there: since all Qs and Bs are being swapped
lexicographic order after the first character is also changed. That might not
be an issue though.
My code relies on the sample data being indicative of the rest of the
data, meaning there'll only be a capital Q, B, or Z at the beginning of
the string.
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Jeff japhy Pinyan% How can we ever be the sold short or
RPI Acacia Brother #734% the cheated, we who for every service
http://www.perlmonks.org/ % have long ago been overpaid?
http://princeton.pm.org/ %-- Meister Eckhart
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RE: sort with special order
JupiterHost.Net wrote:
On Oct 3, JupiterHost.Net said:
I have a list of strings that start with an uppercase B, Q, or Z
I need to sort them so they are in order of Q, B , then Z
Any ideas or input on how to efficiently do that with sort() or even
map() is most appreciated :) perldoc -f sort|-f map didn't appear to
address this situation :(
Jeff 'japhy' Pinyan wrote:
I would use map() before and after sort() to correct leading
characters.
my @sorted =
map { tr/123/QBZ/; $_ }
sort
map { tr/QBZ/123/; $_ }
@data;
Xavier Noria wrote:
They all go in ASCII relative order except B - Q, thus a way to
get it is to handle that special case and delegate to cmp the rest:
my @sorted = sort {
my $x = substr($a, 0, 1) . substr($b, 0, 1);
$x eq BQ || $x eq QB ? $b cmp $a : $a cmp $b;
} @array;
I used the concatenation for clarity, you see the idea anyway if
that's too expensive for your usage.
Brilliant! I'll benchmark those ideas :) Thanks you two!
Read this for an explanation of Jeff's solution:
http://en.wikipedia.org/wiki/Schwartzian_transform
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Re: sort with special order
On 10/3/05, Bakken, Luke [EMAIL PROTECTED] wrote:
JupiterHost.Net wrote:
On Oct 3, JupiterHost.Net said:
I have a list of strings that start with an uppercase B, Q, or Z
I need to sort them so they are in order of Q, B , then Z
Any ideas or input on how to efficiently do that with sort() or even
map() is most appreciated :) perldoc -f sort|-f map didn't appear to
address this situation :(
Jeff 'japhy' Pinyan wrote:
I would use map() before and after sort() to correct leading
characters.
my @sorted =
map { tr/123/QBZ/; $_ }
sort
map { tr/QBZ/123/; $_ }
@data;
Xavier Noria wrote:
They all go in ASCII relative order except B - Q, thus a way to
get it is to handle that special case and delegate to cmp the rest:
my @sorted = sort {
my $x = substr($a, 0, 1) . substr($b, 0, 1);
$x eq BQ || $x eq QB ? $b cmp $a : $a cmp $b;
} @array;
I used the concatenation for clarity, you see the idea anyway if
that's too expensive for your usage.
Brilliant! I'll benchmark those ideas :) Thanks you two!
Read this for an explanation of Jeff's solution:
http://en.wikipedia.org/wiki/Schwartzian_transform
Sort of. Perhaps Randy will chime in here, but as I understand it, the
key to the Schwartzian transform is that the input data 1) doesn't
undergo direct comparison, and 2) is passed by reference, speeding up
the sort, so:
my @sorted =
map { $_-[0] }
sort { $a-[1] cmp $b[1] }
map { [$_, s/^(.)/$1 eq Q ? 1 :
($1 eq B ? 2 :
($1 eq Z ? 3 : $1))/ex] }
@original;
That will slow you down a little with the capturing and substitution,
but is solves Jeff's problem with capital Q, B, or Z later in the
string. I'm not sure how it stacks up to Xaiver's temp variable and
multiple substr calls. This isn't as simple as it looked.
HTH,
-- jay
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Re: sort with special order
Bakken, Luke wrote:
JupiterHost.Net wrote:
On Oct 3, JupiterHost.Net said:
I have a list of strings that start with an uppercase B, Q, or Z
I need to sort them so they are in order of Q, B , then Z
Any ideas or input on how to efficiently do that with sort() or even
map() is most appreciated :) perldoc -f sort|-f map didn't appear to
address this situation :(
Jeff 'japhy' Pinyan wrote:
I would use map() before and after sort() to correct leading
characters.
my @sorted =
map { tr/123/QBZ/; $_ }
sort
map { tr/QBZ/123/; $_ }
@data;
Brilliant! I'll benchmark those ideas :) Thanks you two!
Read this for an explanation of Jeff's solution:
http://en.wikipedia.org/wiki/Schwartzian_transform
Actually Jeff's solution uses the Guttman-Rosler transform:
http://www.sysarch.com/Perl/sort_paper.html
John
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Re: sort with special order
[sorry, PINE has become very confused about who said what]
On Oct 3, Jay Savage said:
On 10/3/05, Bakken, Luke [EMAIL PROTECTED] wrote:
JupiterHost.Net wrote:
On Oct 3, JupiterHost.Net said:
I have a list of strings that start with an uppercase B, Q, or Z
I need to sort them so they are in order of Q, B , then Z
Any ideas or input on how to efficiently do that with sort() or even
map() is most appreciated :) perldoc -f sort|-f map didn't appear to
address this situation :(
Jeff 'japhy' Pinyan wrote:
I would use map() before and after sort() to correct leading
characters.
my @sorted =
map { tr/123/QBZ/; $_ }
sort
map { tr/QBZ/123/; $_ }
@data;
Xavier Noria wrote:
They all go in ASCII relative order except B - Q, thus a way to
get it is to handle that special case and delegate to cmp the rest:
my @sorted = sort {
my $x = substr($a, 0, 1) . substr($b, 0, 1);
$x eq BQ || $x eq QB ? $b cmp $a : $a cmp $b;
} @array;
I used the concatenation for clarity, you see the idea anyway if
that's too expensive for your usage.
Brilliant! I'll benchmark those ideas :) Thanks you two!
Read this for an explanation of Jeff's solution:
http://en.wikipedia.org/wiki/Schwartzian_transform
That will slow you down a little with the capturing and substitution,
but is solves Jeff's problem with capital Q, B, or Z later in the
string. I'm not sure how it stacks up to Xaiver's temp variable and
multiple substr calls. This isn't as simple as it looked.
Actually, I'm using a Guttman-Rosler Transform, not a Schwartzian
Transform. I've actually come up with a slightly less dangerous
technique I believe:
my @sorted =
map substr($_, 1),
sort
map +{qw( Q a B b Z c )}-{substr($_, 0, 1)} . $_,
@original;
Reading from the bottom up:
1. we have the original array
2. using an anonymous hash reference ({Q = 'a', B = 'b', Z = 'c'}), we
select the first character (Q, B, or Z) of the string ($_) and prepend
the value in the hash corresponding that character (a for Q, b for B,
or c for Z)
3. we then sort the modified list of words, with all the 'Q' words being
first (since they are now prepended with 'a'), then all the 'B' words,
then all the 'Z' words
4. then we extract everything AFTER the first character
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http://www.perlmonks.org/ % have long ago been overpaid?
http://princeton.pm.org/ %-- Meister Eckhart
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