Suppose u have a file 
A)1.8  2.5  3.8  1.9  -3.5  -3.5  3.2  -3.9  4.2  4.5  2.8
B)-1.3  -0.9  -0.7  -0.4  -0.8  -3.5  -3.5  -1.6  -4.5
<c>
continue....
That is in a file where in each  line have to calculate mean and varia
+nce where A, B can ignored as just saying that u have  separate line 
+where each line have  input data points in one  file

 program is 
<code>
#!/usr/bin/perl -w
open( FILE, "< file_1" ) or die "Can't open file_1 : $!";
while( <FILE> ){
  @fields = split / /;
  for($i=0;$i < scalar(@fields); $i++ ){
    $sum[$i]+=$fields[$i];
    $sumsq[$i]+=$fields[$i]*$fields[$i];
  }
  $n++;
}

for($i=0;$i < scalar(@sum); $i++ ){
  $sum[$i] /= $n; $sumsq[$i] /= $n;
  $stddev = sqrt( $sumsq[$i] - $sum[$i]*$sum[$i] );
  print( $sum[$i]." ".$stddev." " );
}
close FILE
</code>
But while running the program
error occured 
<c>
rgument "" isn't numeric in addition (+) at meanStddev.pl line 6, <FIL
+E> line 1.
Argument "" isn't numeric in addition (+) at meanStddev.pl line 6, <FI
+LE> line 1.
Argument "" isn't numeric in addition (+) at meanStddev.pl 
Argument "\n" isn't numeric in addition (+) at meanStddev.pl line 6, <
+FILE> line 3.
0.573333333333333 0.867998975933856 0 0 0.833333333333333 1.1785113019
+7758 0 0 1.26666666666667 1.79133717900592 0 0 0.633333333333333 0.89
+566858950296 0 0 -1.16666666666667 1.64991582276861 0 0 -1.1666666666
+6667 1.64991582276861 0 0 1.06666666666667 1.5084944665313 0 0 -1.3 1
+.83847763108502 0 0 1.4 1.97989898732233 0 0 1.5 2.12132034355964 0 0
+ 0.933333333333333 1.31993265821489 0 0 -0.433333333333333 0.61282587
+7028341 0 0 -0.3 0.424264068711929 0 0 -0.233333333333333 0.329983164
+553722 0 0 -0.133333333333333 0.188561808316413 0 0 -0.26666666666666
+7 0.377123616632825 0 0 -1.16666666666667 1.64991582276861 0 0 -1.166
+66666666667 1.64991582276861 0 0 -0.533333333333333 0.754247233265651
+ 0 0 -1.5 2.12132034355964

[download]
any suggestions

20080114 Janitored by Corion: Changed bold tags to code tags

In reply to to calculate mean and variance by cdfd123

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.