02-14-2010
Hi.
Quote:
Originally Posted by ironmask2004
but you need to know how muche recoreds you have insaide the fill to generate a random number betwwen 1 and NUM Of Rec !!!
If one is willing to devote the time and effort, the
reservoir sampling method allows one to extract a random sample in a single pass through a file. A brief explanation along with a python and perl code can be found at
Program-o-Babble: Reservoir Sampling Algorithm in Python and Perl among many other places.
Best wishes ... cheers, drl
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LEARN ABOUT MOJAVE
uri::url
URI::URL(3) User Contributed Perl Documentation URI::URL(3)
NAME
URI::URL - Uniform Resource Locators
SYNOPSIS
$u1 = URI::URL->new($str, $base);
$u2 = $u1->abs;
DESCRIPTION
This module is provided for backwards compatibility with modules that depend on the interface provided by the "URI::URL" class that used to
be distributed with the libwww-perl library.
The following differences exist compared to the "URI" class interface:
o The URI::URL module exports the url() function as an alternate constructor interface.
o The constructor takes an optional $base argument. The "URI::URL" class is a subclass of "URI::WithBase".
o The URI::URL->newlocal class method is the same as URI::file->new_abs.
o URI::URL::strict(1)
o $url->print_on method
o $url->crack method
o $url->full_path: same as ($uri->abs_path || "/")
o $url->netloc: same as $uri->authority
o $url->epath, $url->equery: same as $uri->path, $uri->query
o $url->path and $url->query pass unescaped strings.
o $url->path_components: same as $uri->path_segments (if you don't consider path segment parameters)
o $url->params and $url->eparams methods
o $url->base method. See URI::WithBase.
o $url->abs and $url->rel have an optional $base argument. See URI::WithBase.
o $url->frag: same as $uri->fragment
o $url->keywords: same as $uri->query_keywords
o $url->localpath and friends map to $uri->file.
o $url->address and $url->encoded822addr: same as $uri->to for mailto URI
o $url->groupart method for news URI
o $url->article: same as $uri->message
SEE ALSO
URI, URI::WithBase
COPYRIGHT
Copyright 1998-2000 Gisle Aas.
perl v5.18.2 2012-02-11 URI::URL(3)