Thanks for your great work!
I got the latest 0.6.1 source from github.
My gcc compiler seems to have problem with the Greek letters σ and ω you use as variables in output_panel.c. I changed them to sigma and omega, and the problem went away. Is there an option to set for the compiler to recognize the 8-bit ascii letters so I don't have to change the source code?
Also, on line 22 of the same file, it doesn't like "zoom_mid = (zoom_min + zoom_max)/2" to be declared as static const double, so I replaced them with "#define ......".