The problem can be reproduced on [sagecell]( https://sagecell.sagemath.org/?z=eJxVi0EKhDAMAO99SSKu4t5zEg-5-wFxQy2ILU1W8nx72cPCwMDAcKQ9KzgGNuI4pMsk1s0EvH-V1DeOfH5orV_BMCtNI7y7kjAsTrN2bKHUNsHZHgc2xL-weAu6RRluqZry9fMDXHAoTw==&lang=sage&interacts=eJyLjgUAARUAuQ==), which is currently at 9.1.
HTH, Le dimanche 9 août 2020 16:00:11 UTC+2, Emmanuel Charpentier a écrit : > > *Note : for once, this is a cross-post from ask.sagemath.org > <https://ask.sagemath.org/question/52922/latexing-showing-or-viewing-a-held-integral-triggers-its-evaluation/>, > > for ticket advice…* > > Exploring this ask.sagemath question > <https://ask.sagemath.org/question/52913/error-during-integration-not-of-type-unsigned-byte-15/> > > led me to discover what I think is a serious bug : it seems that latexing > an expression *containing* a held (= unevaluated) integral triggers the > latter’s evaluation ; ditto for viewing or showing… > > Minimal case: > > sage: Ig=sin(x) > sage: It=Ig.integrate(x,-pi,pi,hold=True) > sage: Cs=1/(2*pi) > sage: latex(It) > \int_{-\pi}^{\pi} \sin\left(x\right)\,{d x} > > So far, so good. But : > > sage: Ex=Cs*It > sage: Ex > 1/2*integrate(sin(x), x, -pi, pi)/pi > sage: latex(Ex) > \frac{0}{2 \, \pi} > > Aaaarghh ! And, of course : > > sage: show(Ex) > \newcommand{\Bold}[1]{\mathbf{#1}}\frac{0}{2 \, \pi} > > And view(Ex) proudly displays this crap… > > IMHO, this is a serious bug, entailing a risk of inadvertently triggering > long, impossible or never ending computations. > > Unless someone points me to the direction and magnitude of my stupidity, I > intend to file this as a *critical* (maybe *blocker*) ticket; however, > the target is not clear to me : I do not thoink that the rendering system > is the only culprit (nor even the main one…) ; there may be a more > fundamental problem in the evaluation system. > > Advice ? > > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/81093f9d-32ad-444c-9547-2f31d148e0c8o%40googlegroups.com.
