\[\Im(\left(\frac{e^{x} + e^{-x}}{2} \cdot \cos y + \frac{e^{x} - e^{-x}}{2} \cdot \sin y i\right))\]

\Im(\left(\frac{e^{x} + e^{-x}}{2} \cdot \cos y + \frac{e^{x} - e^{-x}}{2} \cdot \sin y i\right))

double f(double x, double y) {
        double r43388 = x;
        double r43389 = exp(r43388);
        double r43390 = -r43388;
        double r43391 = exp(r43390);
        double r43392 = r43389 + r43391;
        double r43393 = 2.0;
        double r43394 = r43392 / r43393;
        double r43395 = y;
        double r43396 = cos(r43395);
        double r43397 = r43394 * r43396;
        double r43398 = r43389 - r43391;
        double r43399 = r43398 / r43393;
        double r43400 = sin(r43395);
        double r43401 = r43399 * r43400;
        double r43402 = /* ERROR: no complex support in C */;
        double r43403 = /* ERROR: no complex support in C */;
        return r43403;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019323 +o rules:numerics
(FPCore (x y)
  :name "Euler formula imaginary part (p55)"
  :precision binary64
  (im (complex (* (/ (+ (exp x) (exp (- x))) 2) (cos y)) (* (/ (- (exp x) (exp (- x))) 2) (sin y)))))

Backtrace

dict-ref: no value for key: 'branch43387 in: '((x . binary64) (y . binary64))		L	C
for-loop	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt	106	4
make-sampler	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt	99	0
prepare-points	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt	158	0
for-loop	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	233	9
sindices->spoints	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	194	0
f33	/opt/racket-7.2/collects/racket/match/compiler.rkt	507	40
get-final-combination	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	369	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28
run	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28