On Cocalc <https://cocalc.com/projects/d9f9cc53-525c-4d92-a0a7-bc5941b8c734/files/?session=default>, I have checked that the problem can be reproduced on all available Sage kernels back to 8.2.
Looks more like an error from me, rather than a bug… Suggestions most welcome ! Le dimanche 9 août 2020 16:31:47 UTC+2, Emmanuel Charpentier a écrit : > > 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/65a10e87-2a67-4ac5-90a6-21b99c38dee3o%40googlegroups.com.
