Quick Reference

1.3.7.1 Runtime errors

Runtime errors in Yorick are often simple typos, like syntax errors:

> theta = span(0,2*pi,200) > wave = sin(thta)*exp(-0.5*theta) ERROR (*main*) expecting numeric argument WARNING source code unavailable (try dbdis function) now at pc= 1 (of 23), failed at pc= 5 To enter debug mode, type <RETURN> now (then dbexit to get out) >

Many errors of this sort would be detected as syntax errors if you had to declare Yorick variables. Yorick's free-and-easy attitude toward declaration of variables is particularly annoying when the offending statement is in a conditional branch which is very rarely executed. When a bug like that ambushes you, be philosophical: Minutely declared languages will just ambush you in more subtle ways.

Other runtime errors are more interesting; often such a bug will teach you about the algorithm or even about the physical problem:

> #include "damped.i" > theta = span(0, 6*pi, 300) > amplitude = damped_wave(theta, 0.25) ERROR (damped_wave) math library exception handler called LINE: 19 FILE: /home/icf/munro/damped.i To enter debug mode, type <RETURN> now (then dbexit to get out) >

What is an oscillator with a Q of less than one half? Maybe you don't care about the so-called overdamped case -- you really wanted Q to be 2.5, not 0.25. On the other hand, maybe you need to modify the damped_wave function to handle the overdamped case.