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From: sln on 7 May 2010 18:16
On Fri, 7 May 2010 13:33:10 -0700 (PDT), "sopan.shewale(a)gmail.com" <sopan.shewale(a)gmail.com> wrote:

>On May 7, 11:56�pm, s...(a)netherlands.com wrote:
>> On Fri, 7 May 2010 07:24:13 -0700 (PDT), IJALAB <balaji.d...(a)gmail.com> wrote:
>> >Hi,
>>
>> >i have a text file which is comma seperated and i have extracted few
>> >values from the text in an array for example,
>> >30, 1, 4,5, 31, 4, 2, 3, 32, 2,3,0, 38
>>
>> >my goal is to find the max of 30, 31, 32, 38 (i, i+4, i + 8, i+
>> >12....so on)
>> >i have put a split statement and in a loop and captured these 4
>> >elements in an array. how do i find the max of these values, which is
>> >in an array using perl?
>>
>> >thanks
>>
>> This would be my preferred method.
>> $string = join '', <DATA>
>>
>> -sln
>> ---------------
>>
>> use strict;
>> use warnings;
>>
>> my $string = q(30, 1, 4 ,5, -31, 4, 2, 3, 32, 2,3, 0, 38 , 39, 40 );
>> my ($max,$min) = (0,0);
>>
>> for (split / (?: \s*,\s*[^,]*){3} \s* , \s* | \s*, .* $/xs , $string) {
>> � � $max = $_ unless $max > $_ ;
>> � � $min = $_ unless $min < $_ ;}
>>
>> print "min/max = $min, $max\n";
>>
>> __END__
>>
>> min/max = -31, 38

>
>
>
>
>>Once you have array, how about?
>my $max = (sort { $b <=> $a } @array)[0];

Why get an array? But sure why not, I never
met a sort that uses boolean that I didn't like.

-sln
From: John Bokma on 7 May 2010 18:16
Tad McClellan <tadmc(a)seesig.invalid> writes:

> IJALAB <balaji.draj(a)gmail.com> wrote:
>
>> captured these 4
>> elements in an array. how do i find the max of these values, which is
>> in an array using perl?
>
> my($max) = sort {$b <=> $a} @array;

use List::Util 'max';

my $max = max @array;

A linear search /might/ be faster than sorting if @array is large.

See perldoc List::Util

(in my experience an under used module)

--
John Bokma j3b

Hacking & Hiking in Mexico - http://johnbokma.com/
http://castleamber.com/ - Perl & Python Development
From: Tad McClellan on 7 May 2010 21:09
John Bokma <john(a)castleamber.com> wrote:
> Tad McClellan <tadmc(a)seesig.invalid> writes:
>
>> IJALAB <balaji.draj(a)gmail.com> wrote:
>>
>>> captured these 4
>>> elements in an array. how do i find the max of these values, which is
>>> in an array using perl?
>>
>> my($max) = sort {$b <=> $a} @array;

> A linear search /might/ be faster than sorting if @array is large.


He said n=4, which is why I quoted where he said that n=4

:-)


--
Tad McClellan
email: perl -le "print scalar reverse qq/moc.liamg\100cm.j.dat/"
The above message is a Usenet post.
I don't recall having given anyone permission to use it on a Web site.
From: J�rgen Exner on 7 May 2010 22:43
"sopan.shewale(a)gmail.com" <sopan.shewale(a)gmail.com> wrote:
>Once you have array, how about?
>my $max = (sort { $b <=> $a } @array)[0];

If you insist on being inefficient, then that is certainly a good
solution.
Sort is O(n*log n), while computing the max value can easily be done in
O(n).

jue
From: J�rgen Exner on 7 May 2010 22:46
Tad McClellan <tadmc(a)seesig.invalid> wrote:
>John Bokma <john(a)castleamber.com> wrote:
>> Tad McClellan <tadmc(a)seesig.invalid> writes:
>>
>>> IJALAB <balaji.draj(a)gmail.com> wrote:
>>>
>>>> captured these 4
>>>> elements in an array. how do i find the max of these values, which is
>>>> in an array using perl?
>>>
>>> my($max) = sort {$b <=> $a} @array;
>
>> A linear search /might/ be faster than sorting if @array is large.
>
>
>He said n=4, which is why I quoted where he said that n=4

Good catch, I missed it.

jue
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