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.


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
blafunkdat yehaaa
"graphs.gpl", line 9: undefined variable: blu


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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