Re: [Scilab-users] integral of th discontinuous function
Thanks a lot. I understand the character of function "intg". I am going to use "intg" for each continuous interval and sum the results because I can't know where the error is large or not when integrate for one interval. -- View this message in context: http://mailinglists.scilab.org/integral-of-th-discontinuous-function-tp4032242p4032275.html Sent from the Scilab users - Mailing Lists Archives mailing list archive at Nabble.com. ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users
Re: [Scilab-users] integral of th discontinuous function
Le 12/05/2015 18:08, Serge Steer a écrit : .../... in the first case it seems that intg gives quite good results even with a discontinuous function: Actually, the algorithm used by intg() is self-adaptative. It automatically refine the sampling of intervals where the function varies rapidly. However, it is not perfect. Cases with isolated values cannot be always efficiently integrated. Samuel ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users
Re: [Scilab-users] integral of th discontinuous function
Le 12/05/2015 17:31, fujimoto2005 a écrit : > I want to integrate a discontinuous function whose number of discontinuous > points are 3-4. > I know I can get an enough accurate result when I divide whole integrate > range to sub-ranges over which the function is continuous and apply the > standard intergration program such as inttrap for each range and sum the > results. is your function beeing given by a scilab function like y=f(t) or by a sequence (t(k),y(k)) in the first case the inegration of the continuous part can be done using the intg function and in the second one by inttrap. In the second case the notion of discontinuity is not clear because you only have a discret sequence of points in the first case it seems that intg gives quite good results even with a discontinuous function: function y=f(t) if t<=1 then y=sin(t) elseif t<=3 y=10+sin(t) else y=-10*sin(t) end endfunction e=1e-13; i1=intg(0,5,f,e,e); i2=intg(0,1,f,e,e)+intg(1+2*%eps,3,f,e,e)+intg(3+2*%eps,5,f,e,e); i1-i2 ans = 1.421D-14 Serge Steer > But I want to integrate with one whole range. > Is there a such program? > > > > > > > -- > View this message in context: > http://mailinglists.scilab.org/integral-of-th-discontinuous-function-tp4032242.html > Sent from the Scilab users - Mailing Lists Archives mailing list archive at > Nabble.com. > ___ > users mailing list > users@lists.scilab.org > http://lists.scilab.org/mailman/listinfo/users > ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users
[Scilab-users] integral of th discontinuous function
I want to integrate a discontinuous function whose number of discontinuous points are 3-4. I know I can get an enough accurate result when I divide whole integrate range to sub-ranges over which the function is continuous and apply the standard intergration program such as inttrap for each range and sum the results. But I want to integrate with one whole range. Is there a such program? -- View this message in context: http://mailinglists.scilab.org/integral-of-th-discontinuous-function-tp4032242.html Sent from the Scilab users - Mailing Lists Archives mailing list archive at Nabble.com. ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users
