Re: [fricas-devel] a limit failure
(1) -> f:=differentiate(complexNormalize(log(tan(%pi/2*tanh(x,x); Type: Expression(Integer) (2) -> output lines(formatExpression(f)$Format1D).1 (-8*%pi*(%e^x)^2*%e^((%pi*sqrt(-1)*(%e^x)^2+(-%pi)*sqrt(-1))/((%e^x)^2+1)))/( (sqrt(-1)*(%e^x)^4+2*sqrt(-1)*(%e^x)^2+sqrt(-1))*(%e^((%pi*sqrt(-1)*(%e^x)^2+ (-%pi)*sqrt(-1))/((%e^x)^2+1)))^2+(-sqrt(-1))*(%e^x)^4+-2*sqrt(-1)*(%e^x)^2-s qrt(-1)) Type: Void (3) -> limit(f,x=%plusInfinity) (3) 2 Type: Union(OrderedCompletion(Expression(Integer)),...) On Wed, 23 Nov 2022 at 12:48, Waldek Hebisch wrote: > On Wed, Nov 23, 2022 at 05:21:42PM +0800, Qian Yun wrote: > > FYI, it can be correctly solved by "mrv_limit" which uses Gruntz > > algorithm. However I don't know why this code path is not enabled > > for this function. (see "is_exp_log" in limitps.spad). > > > > - Qian > > > > (1) -> )expose MrvLimitPackage > >MrvLimitPackage is now explicitly exposed in frame frame1 > > (1) -> f := D(log(tan(%pi/2*tanh(x))), x); > > > > Type: > > Expression(Integer) > > (2) -> mrv_limit(f, x=%plusInfinity) > > > >(2) 2 > > This is due to 'tan'. Termination of Gruntz algorithm depends > on having exp-log function, for trigonometric functions > Gruntz may fail. This is easy case, but ATM we have no way > to distinguish it from problematic cases. > > -- > Waldek Hebisch > > -- > You received this message because you are subscribed to the Google Groups > "FriCAS - computer algebra system" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to fricas-devel+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/fricas-devel/20221123174757.GA25181%40fricas.math.uni.wroc.pl > . > -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to fricas-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/fricas-devel/CAC6x94SGNmRxdACtiyWpUAqCTJJ72pAdo6jWJadyewpBVnSi7w%40mail.gmail.com.
Re: [fricas-devel] a limit failure
On Wed, Nov 23, 2022 at 05:21:42PM +0800, Qian Yun wrote: > FYI, it can be correctly solved by "mrv_limit" which uses Gruntz > algorithm. However I don't know why this code path is not enabled > for this function. (see "is_exp_log" in limitps.spad). > > - Qian > > (1) -> )expose MrvLimitPackage >MrvLimitPackage is now explicitly exposed in frame frame1 > (1) -> f := D(log(tan(%pi/2*tanh(x))), x); > > Type: > Expression(Integer) > (2) -> mrv_limit(f, x=%plusInfinity) > >(2) 2 This is due to 'tan'. Termination of Gruntz algorithm depends on having exp-log function, for trigonometric functions Gruntz may fail. This is easy case, but ATM we have no way to distinguish it from problematic cases. -- Waldek Hebisch -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to fricas-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/fricas-devel/20221123174757.GA25181%40fricas.math.uni.wroc.pl.
Re: [fricas-devel] a limit failure
FYI, it can be correctly solved by "mrv_limit" which uses Gruntz algorithm. However I don't know why this code path is not enabled for this function. (see "is_exp_log" in limitps.spad). - Qian (1) -> )expose MrvLimitPackage MrvLimitPackage is now explicitly exposed in frame frame1 (1) -> f := D(log(tan(%pi/2*tanh(x))), x); Type: Expression(Integer) (2) -> mrv_limit(f, x=%plusInfinity) (2) 2 On 11/21/22 02:34, 'Martin R' via FriCAS - computer algebra system wrote: Apparently, the following should give 2: (1) -> f := D(log(tan(%pi/2*tanh(x))), x) (2) -> limit(f, x=%plusInfinity) (2) "failed" see https://trac.sagemath.org/ticket/34757 Best wishes, Martin -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to fricas-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/fricas-devel/8e78be18-7f75-b430-35c8-02e6b0515c0e%40gmail.com.
[fricas-devel] a limit failure
Apparently, the following should give 2: (1) -> f := D(log(tan(%pi/2*tanh(x))), x) (2) -> limit(f, x=%plusInfinity) (2) "failed" see https://trac.sagemath.org/ticket/34757 Best wishes, Martin -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to fricas-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/fricas-devel/3f6c7886-f6c8-47d6-86a3-6f56247cbaf4n%40googlegroups.com.
