Hi!
I'm trying to sort a file.dat with the sort command. The data contained by file.dat is similar to the data set below:
100.000
99.000
110.000
55.000
113.000
33.000
25.000
9.000
15.000
It is relatively easy to sort the data in ascending or descending order, but the problem is that the separating empty rows between the blocks are put on top of the sorted file. I wish to keep the empty rows and sort the data blocks separately, like this:
99.000
100.000
110.000
33.000
55.000
113.000
9.000
15.000
25.000
Can anybody please help me?
And also I must mention that I'm quite new at UNIX scripting, so try to explain in plain English :o!
Hehe!
First of all I want to give my appreciation for a quick answer.
Without knowing what the heck that code from Ygor meant I tested it in my script. It seemed to work partially in my case, but as a result of my own lazyness it did not give me the result I need.
The columns represent x-, y- and z-coordinates.
I wish to sort the columns with x- and y-coordinates in ascending order.
Data is also supposed to be written back to data.dat
I apologize for any inconvenience and humbly ask you to help me again.
It is also in my interest to understand the prospective code which is given.
Where can I get a good tutorial on gawk?
The code worked just fine! Thanks, you are a life-saver!! But then another problem occured. After redirecting the sorted data into a new file "datanew.dat", it was to be plotted using gnuplot. gnuplot is invoked using the same script in which the "sorting" code is implemented. It seems like the sorting process and data redirect finishes after gnuplot is initiated. Which then results in a gnuplot request of a file that is not yet created. I'm sure there is away to do this but my familiarity with ruby is rather slim. So once again I turn to you for help.
Can I somehow stall the initiation of gnuplot until the sorting and redirecting (resulting in datanew.dat) are finished?
the active parts of the script are shown below:
# I want this process to end before continuing to the next (invoking GNUplot)
ruby -00ne'puts split("\n").sort_by{|x|x[/\s\S+/].to_f};puts' data.dat > datanew.dat
#Invoking gnuplot with input file gnu.ini
gnuplot gnu.ini
"gnu.ini" contains all plot properties such as labels, gridsize, ticlevel etc, including the command to plot datanew.dat.
When a problem can be solved so elegantly with your code solution, I would be stupid not to use it . Once again, thanks futurelet! I must admit, I do not understand the code presented but I will make an effort to do so.
What is your shell's command to make the script pause for x seconds?
Try inserting that after the Ruby line.
An explanation of the code:
ruby -00ne'puts split("\n").sort_by{|x|x[/\s\S+/].to_f};puts' file
Switches:
00 Make the record-separator an empty line. (In Awk, RS="".)
n Automatically read each record of the file, as Awk does.
e Program follows.
Program:
split("\n)
Short for $_.split("\n"). $_ is the record just read ($0 in Awk).
The array created by split is then sorted by sort_by, which
is a built-in implementation of the "Schwartzian Transform"
that Perlers drool about.
{ |x| x[/\s\S+/].to_f }
This is the code-block passed to sort_by. x is the parameter;
an element of the array.
x[ /\s\S+/ ] This means "give me the part of the string x
that is matched by the regular expression." \s is whitespace;
\S is non-whitespace. This grabs the 2nd field.
The matching substring is then converted to a floating-point
number by .to_f
So sort_by sorts the array on the 2nd field, with each item
treated as a float, not a string.
puts simply prints with appended linefeed; it cleverly prints
each item of an array on a separate line.
. Once again, thanks futurelet! I must admit, I do not understand the code presented but I will make an effort to do so.