Thanks a lote for your useful comments. GM.
El jue., 7 jul. 2022 11:09, Niranjana K M <niranjan...@gmail.com> escribió: > Apart from just looking at this particular plot and trying to manage it, > look at the actual problem in depth. Please look at how plotting points are > evaluated. Even though Sage is capable of evaluating these points, it (or > matplotlib?) is evaluating y coordinates after 88 as inf or nan. > > Please see my post above with one evaluation with > for T in srange(1,100,1.0): > and another with > for T in srange(1,100,1): > The difference is that the increment is a float. And also range(1,100,1) > produces the same result as srange(1,100,1). > > Also, > > parametric_plot(C, (t,89.0,95.0)) > clearly says that here the y values above 88 are evaluated as inf or nan > even though they are not and Sage is capable of evaluating them correctly. > > What if these things creep into plotting ranges which we are really > interested in, where we expect y value to be a finite value but the program > calculates as inf or nan. > > Here one thing to observe is that the vertical line is appearing > because after 88 the y value is wrongly calculated as inf or nan and the > plotter is turning them into 0 to handle it and hence the plot suddenly > falls to y=0 (x is not affected though). > > > *Regards* > *Niranjana* > > > On Thu, Jul 7, 2022 at 12:44 AM Samuel Lelievre <samuel.lelie...@gmail.com> > wrote: > >> In case the hope in extending the range of t further and further >> was to capture the missing portion of the curve, it turns out >> the problem is at the other end, near zero. >> >> The curve is missing its initial segment, because >> >> - parametric_plot(C, (t, a, b)) uses equispaced evaluation points >> along the interval [a, b], skipping points where evaluation fails >> - C cannot be evaluated at zero >> - C travels quite some distance when t runs through (0, 0.01) >> >> To better view the curve, plot an initial arc separately, >> say for t in the interval (10^-9, 10^-2); then the rest of >> the curve, say up to t = 7. >> ``` >> pa = parametric_plot(C, (t, 1e-9, 1e-2), color='steelblue') >> pb = parametric_plot(C, (t, 1e-2, 7), color='steelblue') >> p = pa + pb >> p.show() >> ``` >> >> There is not much point plotting further than t = 7. >> Check how short the arc for t running along [7, 88] is: >> ``` >> pc = parametric_plot(C, (t, 7, 88), color='firebrick') >> pc.show(xmin=-1.001, xmax=-0.999, ymin=0.495, ymax=0.505, >> aspect_ratio=1/10) >> ``` >> >> -- >> You received this message because you are subscribed to a topic in the >> Google Groups "sage-devel" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/sage-devel/5GkgeGQjr7A/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> sage-devel+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/sage-devel/dd9fa495-fd3e-44d4-83ba-1f77ed235144n%40googlegroups.com >> <https://groups.google.com/d/msgid/sage-devel/dd9fa495-fd3e-44d4-83ba-1f77ed235144n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-devel+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sage-devel/CAMcUJ1t%3Dym%3D5YqKaGA6JF2dY2Kgs_PTD8mggLDyCsz%3D_UwAsHQ%40mail.gmail.com > <https://groups.google.com/d/msgid/sage-devel/CAMcUJ1t%3Dym%3D5YqKaGA6JF2dY2Kgs_PTD8mggLDyCsz%3D_UwAsHQ%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/CAGkGnRa04pdQOSG_krorxyttF4zhdC8%2Bib_zNT_oEjP9OLHKZw%40mail.gmail.com.
