BashScript to organize a given txt file - linux

Question

I have a txt file of single column that I will like to divide into multiple columns and label them.
I've tried what I know, but the division is not what I want.
I have a ivmeasurementff.txt which contains:
24.000000
0.003207
0.000002
25.000000
0.003435
0.000002
26.000000
0.003991
0.000002
27.000000
0.003207
0.000002
28.000000
0.003232
0.000002
29.000000
0.003283
pr -ts" " --columns 2 ivmeasurementff.txt
This code just split the column into two
Expected output:
Actual Vol T Vol Current
24.000000 0.003207 0.000002
25.000000 0.003435 0.000002
26.000000 0.003991 0.000002
Actual output:
24.000000 0.003435
0.003207 0.000002
0.000002 26.000000
25.000000 0.003991

Answer 1

You may use paste to format it into 3 columns:
paste - - - < ivmeasurementff.txt
Since there's no header, you have to manually add it:
echo "Actual Vol\tT Vol\tCurrent"; paste - - - < ivmeasurementff.txt

Answer 2

Simple solution with xargs:
xargs -n 3 < Input-file
Or if you are ok with awk.
awk 'FNR%3==0 && FNR!=1{print val,$0;val="";next} {val=(val?val OFS:"")$0} END{if(val){print val}}' Input_file
perl solution:
perl -pe 's{\n$}{ } if $. % 3' Input_file

Answer 3

Take a look at https://docstore.mik.ua/orelly/unix3/upt/ch21_15.htm
Under 21.15.3 it suggests using the -l option
pr -ts" " -l1 -3 ivmeasurementff.txt
24.000000 0.003207 0.000002
25.000000 0.003435 0.000002
26.000000 0.003991 0.000002
27.000000 0.003207 0.000002
28.000000 0.003232 0.000002
29.000000 0.003283
Quoting:
21.15.3. Order Lines Across Columns: -l
Do you want to arrange your data across the columns, so that the first three lines print across the top of each column, the next three lines are the second in each column, and so on, like this?
% pr -l1 -t -3 file1
Line 1 here Line 2 here Line 3 here
Line 4 here Line 5 here Line 6 here
Line 7 here Line 8 here Line 9 here
... ... ...
Use the -l1 (page length 1 line) and -t (no title) options. Each "page" will be filled by three lines (or however many columns you set). You have to use -t; otherwise, pr will silently ignore any page lengths that don't leave room for the header and footer. That's just what you want if you want data in columns with no headings.

Answer 4

Simply add option -a and specify three columns.
$ pr -ats" " --columns 3 ivmeasurementff.txt
24.000000 0.003207 0.000002
25.000000 0.003435 0.000002
26.000000 0.003991 0.000002
27.000000 0.003207 0.000002
28.000000 0.003232 0.000002
29.000000 0.003283
I'm not sure why this works. Seems like pr treats columns as rows in some cases?