methods to convert text data to line charts

[Steve Post]

I have text files with data in it. I want to filter it, and make line charts by day (or month, or minute, or...).

Here's one way I could do it. I have the text files. I use perl to filter and reformat them. I take the new formated text file and use perl with a linechart module to plot it. Or I could take the formated text file and throw it into excel to make a line chart. This seems primitive to me. I'm doing a lot of manual processes. I would like to automate it.

On the other hand, I have tons of flexibility because it is so primitive. I wouldn't want a fancy program that refuses to let me specify what data I want to plot. For example, I would not expect a program to give me blocks per second on disk c3t2d0 daily at 9:02am without weekends from 1Feb2006 until now. But I would expect a program to plot a column of numbers by date.

So has somebody already gone down this road? What did YOU do?

[James R. Ferguson · Accepted solution]

Hi Steve:

I use Perl to do the parsing, summarizing and formatting. I find nothing intrinsically wrong with taking that output and importing it into Excel to make graphs. In fact, that has been the road I have traveled too.

After all, the Unix way is to do one thing well, passing input and output down a chain (pipe) of tools you cobble together to affect a solution.

Certainly some folks use the GNU plotting tools and that's fine too.

REgards!

...JRF...

[Steve Post]

I waited on the points to see if anybody else would write.


It looks like gnuplot is exactly what I want.
I have the data in format:

mm/dd/yy ### ### ### ###
gnuplot> set xdata time
gnuplot> set timefmt "%m\/%d\/%y"
gnuplot> plot "day_7.dat" using 1:2 with lines,\
"day_7.dat" using 1:3 with lines,\
"day_7.dat" using 1:4 with lines

I hit return, and I get a nice graph.
Now I'm pretty sure I will be able to run gnuplot non-interactively from a perl script.
The biggest hurtle for me has been properly getting the date read in as the X axis. This gnuplot gets me past that hurtle.

thanks.
steve