Octave 3.8, jcobi/2

Specification

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\[\left(\alpha > -1 \land \beta > -1\right) \land i > 0\]
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\alpha + \beta\right) + 2 \cdot i\\ \frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{t\_0}}{t\_0 + 2} + 1}{2} \end{array} \end{array} \]
(FPCore (alpha beta i)
 :precision binary64
 (let* ((t_0 (+ (+ alpha beta) (* 2.0 i))))
   (/ (+ (/ (/ (* (+ alpha beta) (- beta alpha)) t_0) (+ t_0 2.0)) 1.0) 2.0)))
double code(double alpha, double beta, double i) {
	double t_0 = (alpha + beta) + (2.0 * i);
	return (((((alpha + beta) * (beta - alpha)) / t_0) / (t_0 + 2.0)) + 1.0) / 2.0;
}
real(8) function code(alpha, beta, i)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8), intent (in) :: i
    real(8) :: t_0
    t_0 = (alpha + beta) + (2.0d0 * i)
    code = (((((alpha + beta) * (beta - alpha)) / t_0) / (t_0 + 2.0d0)) + 1.0d0) / 2.0d0
end function
public static double code(double alpha, double beta, double i) {
	double t_0 = (alpha + beta) + (2.0 * i);
	return (((((alpha + beta) * (beta - alpha)) / t_0) / (t_0 + 2.0)) + 1.0) / 2.0;
}
def code(alpha, beta, i):
	t_0 = (alpha + beta) + (2.0 * i)
	return (((((alpha + beta) * (beta - alpha)) / t_0) / (t_0 + 2.0)) + 1.0) / 2.0
function code(alpha, beta, i)
	t_0 = Float64(Float64(alpha + beta) + Float64(2.0 * i))
	return Float64(Float64(Float64(Float64(Float64(Float64(alpha + beta) * Float64(beta - alpha)) / t_0) / Float64(t_0 + 2.0)) + 1.0) / 2.0)
end
function tmp = code(alpha, beta, i)
	t_0 = (alpha + beta) + (2.0 * i);
	tmp = (((((alpha + beta) * (beta - alpha)) / t_0) / (t_0 + 2.0)) + 1.0) / 2.0;
end
code[alpha_, beta_, i_] := Block[{t$95$0 = N[(N[(alpha + beta), $MachinePrecision] + N[(2.0 * i), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(N[(N[(alpha + beta), $MachinePrecision] * N[(beta - alpha), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision] / N[(t$95$0 + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\alpha + \beta\right) + 2 \cdot i\\
\frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{t\_0}}{t\_0 + 2} + 1}{2}
\end{array}
\end{array}

Reproduce

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herbie shell --seed 2024277 
(FPCore (alpha beta i)
  :name "Octave 3.8, jcobi/2"
  :precision binary64
  :pre (and (and (> alpha -1.0) (> beta -1.0)) (> i 0.0))
  (/ (+ (/ (/ (* (+ alpha beta) (- beta alpha)) (+ (+ alpha beta) (* 2.0 i))) (+ (+ (+ alpha beta) (* 2.0 i)) 2.0)) 1.0) 2.0))

Please file a bug report with this information.

Backtrace

rival-apply: contract violation expected: (or/c ^TYPE? boolean?) given: 0 in: an element of the 2nd argument of (-> rival-machine? (vectorof (or/c ^TYPE? boolean?)) (vectorof any/c)) contract from: <pkgs>/rival/main.rkt blaming: <pkgs>/herbie/core/rival.rkt (assuming the contract is correct) at: <pkgs>/rival/main.rkt:95:24LC
raise-blame-error/usr/share/racket/collects/racket/contract/private/blame.rkt3460
loop.../private/map.rkt4019
vector-map/update/usr/share/racket/collects/racket/vector.rkt620
vector-map/usr/share/racket/collects/racket/vector.rkt1060
rival-apply/home/nightlies/.local/share/racket/8.10/pkgs/rival/eval/main.rkt650
(unnamed)/usr/share/racket/collects/racket/contract/private/arrow-val-first.rkt48618
(unnamed)/home/nightlies/herbie/zane-concrete-values/src/core/rival.rkt764
real-apply/home/nightlies/herbie/zane-concrete-values/src/core/rival.rkt670
(unnamed).../private/arrow-val-first.rkt48618
<eval-prog-real>/home/nightlies/herbie/zane-concrete-values/src/core/sampling.rkt1362
compute-local-errors/home/nightlies/herbie/zane-concrete-values/src/core/localize.rkt2160
actual-errors/home/nightlies/herbie/zane-concrete-values/src/core/explain.rkt350
generate-timelines/home/nightlies/herbie/zane-concrete-values/src/core/explain.rkt4980
explain!/home/nightlies/herbie/zane-concrete-values/src/core/mainloop.rkt3230
run-improve!/home/nightlies/herbie/zane-concrete-values/src/core/mainloop.rkt450
get-alternatives/report/home/nightlies/herbie/zane-concrete-values/src/api/sandbox.rkt1860
(unnamed)/home/nightlies/herbie/zane-concrete-values/src/api/sandbox.rkt2826
(unnamed)/usr/share/racket/pkgs/profile-lib/main.rkt4010
profile-thunk/usr/share/racket/pkgs/profile-lib/main.rkt90
(unnamed)/usr/share/racket/collects/racket/engine.rkt4224