Your syntax is fine: You're creating an array called @var, indexed from 0 to 2, and printing the middle element. To do this from the command line:
Since you got the manpages, read "perlrun" for details on the "-e" switch and other nifty stuff you can do. There are more comments to make, but since you're just getting started, do what it says in the main perl manpage and read the first 5 or 6 in the order given.
Hi
Is there any way to use UNIX and Perl to automate sending e-mail. I got a dynamic changing file that send out to people in my mailing list and want to experinment to see if Perl and UNIX can send it out for me when the content is change. I found a Perl source code but dont really know how to... (4 Replies)
Does anyone know how I can add a variable to a one line perl command such as the following:
#! /bin/bash
date=`date +%Y%m%d`
perl -i -pe 's/(1\.1\.0\.).+/${1}${date}/' ./build_date
I'd like the ${date} variable to be evaluated by the perl command. So that the perl command will read each... (2 Replies)
Hi,
My perl script takes few switches which i'm parsing through GetOpt::Long module.
My script looks like something :
myscript.pl --file="foo" --or --file="bar"
The --file switch takes 2 arguments foo and bar.
The 2 values of file are separated by --or switch. I want to ensure that... (1 Reply)
I had posted previously about this problem I had.
I have multiple text files with hundreds of lines of the following type:
2000001 34 54 234 2000001
32 545 2000001 -2000001 77 2000001 44 2000001 998 2000001
77 32 2000001 45 23 111 89
98 75 23 34 999
.
.
.
etc...
What I wanted was... (2 Replies)
Hi all,
I want to get options from command line by perl.
usage()
options:
-h Show this help message and exit
-t Name of tester
--timeout Set the timeout
-l ... (1 Reply)
Hi,
I use find command to list all the files in a directory and its sub-directories, but the problem is to exclude certain directories during search. Can i give the directory names in command line to skip them and search rest of the directories?
For example i have directories:
test
../test1... (1 Reply)
so in unix this command works works and shows me a list of directories
find . -name \*.xls -exec dirname {} \; | sort -u | > list.txt
but when i try running a perl script to run this command
my $query = 'find . -name \*.xls -exec dirname {} \; | sort -u | > list.txt';... (2 Replies)
how do i check if a command line argument is -g?
for example,
if command line argument equals "-g"
{
print "Goodbye \n";
}
else
{
print "Welcome to the program! \n";
} (1 Reply)
Hi
I need to write a Perl script that the file given as first argument of the command line that will find all occurrences of the string given as the third argument of the command line and replace with the string given as the fourth argument. Name newfound file is specified as the second... (3 Replies)
I am looking for help in processing of those options: '-n' or '-p'
I understand what they do and how to use them.
But, I would like to use them with more than one file (and without any shell-loop; loading the 'perl' once.)
I did try it and -n works on 2 files.
Question is:
- is it possible to... (6 Replies)
Discussion started by: alex_5161
6 Replies
LEARN ABOUT DEBIAN
statistics::basic::variance
Statistics::Basic::Variance(3pm) User Contributed Perl Documentation Statistics::Basic::Variance(3pm)NAME
Statistics::Basic::Variance - find the variance of a list
SYNOPSIS
Invoke it this way:
my $variance = variance(1,2,3);
Or this way:
my $v1 = vector(1,2,3);
my $var = var($v1);
And then either query the values or print them like so:
print "The variance of $v1: $variance
";
my $vq = $var->query;
my $v0 = 0+$var;
Create a 20 point "moving" variance like so:
use Statistics::Basic qw(:all nofill);
my $sth = $dbh->prepare("select col1 from data where something");
my $len = 20;
my $var = var()->set_size($len);
$sth->execute or die $dbh->errstr;
$sth->bind_columns( my $val ) or die $dbh->errstr;
while( $sth->fetch ) {
$var->insert( $val );
if( defined( my $v = $var->query ) ) {
print "Variance: $v
";
}
# This would also work:
# print "Variance: $v
" if $var->query_filled;
}
METHODS
new()
The constructor takes a list of values, a single array ref, or a single Statistics::Basic::Vector as arguments. It returns a
Statistics::Basic::Variance object.
Note: normally you'd use the mean() constructor, rather than building these by hand using "new()".
query_mean()
Returns the Statistics::Basic::Mean object used in the variance computation.
_OVB::import()
This module also inherits all the overloads and methods from Statistics::Basic::_OneVectorBase.
AUTHOR
Paul Miller "<jettero@cpan.org>"
I am using this software in my own projects... If you find bugs, please please please let me know. :) Actually, let me know if you find it
handy at all. Half the fun of releasing this stuff is knowing that people use it.
OVERLOADS
This object is overloaded. It tries to return an appropriate string for the calculation or the value of the computation in numeric
context.
In boolean context, this object is always true (even when empty).
COPYRIGHT
Copyright 2012 Paul Miller -- Licensed under the LGPL
SEE ALSO perl(1), Statistics::Basic, Statistics::Basic::_OneVectorBase, Statistics::Basic::Vector
perl v5.14.2 2012-01-23 Statistics::Basic::Variance(3pm)