Re: how to place rows information into column (2)

I wouldn't try to pattern match the scientific float... you could, but I think it's over-kill. If the data is tab delimited, then you can use that to distinguish the two values:

use strict;
while(<DATA>)
{
  # Get rid of trailing \n on line.
  chomp;

  # divide the line into two items based on tab
  my ($x, $y) = split("\t");    
  print "X:[$x]  Y: [$y]\n";
}

##OUTPUT:
# X:[0.000000e+000]  Y: [1.502947e+000]
# X:[1.162272e-012]  Y: [1.508957e+001]
# X:[2.324544e-012]  Y: [1.508948e+000]
# X:[0.000000e+000]  Y: [1.502947e+001]
# X:[1.162272e-012]  Y: [1.508941e+001]
# X:[2.324544e-012]  Y: [1.508940e+000]
# X:[0.000000e+000]  Y: [1.503947e+000]
# X:[1.162272e-012]  Y: [1.504947e+000]
# X:[2.324544e-012]  Y: [1.508900e+001]

##NOTE in data the two fields are tab delimited.

__DATA__
0.000000e+000    1.502947e+000
1.162272e-012    1.508957e+001
2.324544e-012    1.508948e+000
0.000000e+000    1.502947e+001
1.162272e-012    1.508941e+001
2.324544e-012    1.508940e+000
0.000000e+000    1.503947e+000
1.162272e-012    1.504947e+000
2.324544e-012    1.508900e+001
[download]

"Look, Shiny Things!" is not a better business strategy than compatibility and reuse.

Comment on Re: how to place rows information into column (2) Download Code

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Re^2: how to place rows information into column (2) by sh1tn (Priest) on Feb 02, 2005 at 23:20 UTC
wouldn't try to pattern match the scientific float... you could, but I think it's over-kill. Do you really have any idea what does `/^(\S+)\s+(\S)/o` do? `/^(\S+)\s+(\S)/o and print FH "K: ", $1, "V: ", $2, "\n" while <DATA> +;` [download] where <DATA> contains over 22000 lines - less than a second on my old (less than 1800 Mh cpu) home machine.	[reply] [d/l] [select]
Re^3: how to place rows information into column (2) by osunderdog (Deacon) on Feb 02, 2005 at 23:35 UTC
`/^(\S+)\s+(\S)/o` Matches one or more non-whitespace characters, followed by one or more whitespace characters, followed by 0 or more non-whitespace characters. The `o` indicates 'compile pattern only once'. from `perldoc perlop` `If you want such a pattern to be compiled only once, add a "/o" after +the trailing delimiter. This avoids expensive run-time recompilation +s, and is useful when the value you are interpolating won’t change ov +er the life of the script.` [download] The parens capture those non-whitspace matches into variables `$1` and `$2` for use within the scope. "Look, Shiny Things!"* is not a better business strategy than compatibility and reuse.	[reply] [d/l] [select]