surf error

[Ekin Akoglu]

Dear users,

Thank you all for your comments and suggestions. I have already 
installed gnuplot but the problem persists. Could you please tell me how 
to define the have_newer_gnuplot function? And I don't know why but I 
installed octave today and in repos it was version 2.9.19. But it is 
surprising to me that it seems until now no one has encountered a 
similar problem :). Anyway, thank you all again for your comments.

Regards,

Ekin