AVR-Chat

In an email timestamped Mon, 30 Jan 2006 10:31:01 -0000, Richard Reeves 
said:

"[..]
However, if I un-comment the trig=sin(M_PI) line, I get the
error "../gcc_test.c:21: undefined reference to `sin'"

[..], but why is the error saying what it is?"

You should link the math library with the -lm command line switch.