Gnuplot

Gnuplot is a wonderful graphing program! It works on linux, windows, and other OS's. As of version 4.2 lots of new goodies has arrived. String manipulation and macros are nice features.

Links

String Constants/Variables and Macros

I had some difficulties to understand how it evaluates different strings and how it differed to macros, so I made some tests to see how they work.

set macros
blubla = "funkdat"
test1 = "blu"
test2 = "bla"
test3 = test1.test2 #concatenate strings
test4 = test2.@test3." yehaaa"
print test3
print @test3
print test4
print @test1

#This yields the following output
blubla
funkdat
blafunkdat yehaaa
"graphs.gpl", line 9: undefined variable: blu

Debugging

When plotting datafiles remember to NOT have any empty lines in the dataset. This can really be a major screw-up that is very hard to find indeed.

Line and Point Types

A lot of the default types that gnuplot chooses are rather nice, but many times it necessary to distinguish and use specific point types and line types. I have generated a huge gnuplot list using the gnuplot test function and then some image manipulation. I always lack this information and couldn't find any reference for this on the internet.

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