Exception for quadm (p42, negative)

Specification

Math

\[\begin{array}{l} \\ \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \end{array} \]

FPCore

(FPCore (a b c)
 :precision binary64
 (/ (- (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))

C

double code(double a, double b, double c) {
	return (-b - sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a);
}

Fortran

real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = (-b - sqrt(((b * b) - (4.0d0 * (a * c))))) / (2.0d0 * a)
end function

Java

public static double code(double a, double b, double c) {
	return (-b - Math.sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a);
}

Python

def code(a, b, c):
	return (-b - math.sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a)

Julia

function code(a, b, c)
	return Float64(Float64(Float64(-b) - sqrt(Float64(Float64(b * b) - Float64(4.0 * Float64(a * c))))) / Float64(2.0 * a))
end

MATLAB

function tmp = code(a, b, c)
	tmp = (-b - sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a);
end

Wolfram

code[a_, b_, c_] := N[(N[((-b) - N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]

Reproduce

herbie shell --seed 2024238 
(FPCore (a b c)
  :name "quadm (p42, negative)"
  :precision binary64
  :herbie-expected 10

  :alt
  (! :herbie-platform default (let ((sqtD (let ((x (* (sqrt (fabs a)) (sqrt (fabs c))))) (if (== (copysign a c) a) (* (sqrt (- (fabs (/ b 2)) x)) (sqrt (+ (fabs (/ b 2)) x))) (hypot (/ b 2) x))))) (if (< b 0) (/ c (- sqtD (/ b 2))) (/ (+ (/ b 2) sqtD) (- a)))))

  (/ (- (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))

Please file a bug report with this information.

Backtrace

error: contract violation expected: string? given: 'neg.f64		L	C
f345	.../match/compiler.rkt	559	40
loop	.../private/map.rkt	40	19
loop	.../private/map.rkt	40	19
loop	.../private/map.rkt	40	19
loop	.../private/map.rkt	40	19
loop	.../private/map.rkt	40	19
loop	.../private/map.rkt	40	19
loop	.../private/map.rkt	40	19
loop	.../private/map.rkt	40	19
loop	.../private/map.rkt	40	19
loop	.../private/map.rkt	40	19
loop	.../private/map.rkt	40	19
loop	.../private/map.rkt	40	19
compile-expr	/home/nightlies/herbie/bhargav-log-space/src/core/explain.rkt	70	0
explain	/home/nightlies/herbie/bhargav-log-space/src/core/explain.rkt	614	0
explain!	/home/nightlies/herbie/bhargav-log-space/src/core/mainloop.rkt	321	0
run-improve!	/home/nightlies/herbie/bhargav-log-space/src/core/mainloop.rkt	43	0
get-alternatives/report	/home/nightlies/herbie/bhargav-log-space/src/api/sandbox.rkt	184	0
(unnamed)	/home/nightlies/herbie/bhargav-log-space/src/api/sandbox.rkt	280	6
(unnamed)	/usr/local/racket/share/pkgs/profile-lib/main.rkt	40	10
profile-thunk	/usr/local/racket/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/usr/local/racket/collects/racket/engine.rkt	42	24