+ case OP_RAD2DEG:
+ stackunderflow(0);
+ rpnstack -> s[stptr] = 57.29577951 * rpnstack -> s[stptr];
+ break;
+ case OP_DEG2RAD:
+ stackunderflow(0);
+ rpnstack -> s[stptr] = 0.0174532952 * rpnstack -> s[stptr];
+ break;
+ case OP_ATAN2:
+ stackunderflow(1);
+ rpnstack -> s[stptr-1]= atan2(
+ rpnstack -> s[stptr-1],
+ rpnstack -> s[stptr]);
+ stptr--;
+ break;