<html>Hello,<br /><br />It seems that this value is below %eps==2.2e-16, so I though that once encoded in double the difference between 2e-20 and 0 is too small to be properly taken into account.<br />Am I missing something?<br /><br />Antoine<br /><br /><br />Le Lundi, Mars 09, 2020 15:11 CET, Chin Luh Tan <chinluh.tan@bytecode-asia.com> a écrit:<br /> <blockquote type="cite" cite="170bfa31df1.df4ebe1b18591.9003660211809807661@bytecode-asia.com"> </blockquote><meta content="text/html;" http-equiv="Content-Type"><div style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10pt;"><div>initially I thought could it be possible the number is too small (or too large) to be handled by double? </div><div> </div><div>after trying scaling down the problem, I notice that in Scilab 6.0.2 onwards:</div><div> </div><div>--> 2e-20*%i</div><div>ans =</div><div> </div><div> 0. </div><div> </div><div>in Scilab 5.5.2</div><div> </div><div>-->2e-20*%i</div><div>ans =</div><div> </div><div> 2.000D-20i </div><div> </div><div> </div><div>Could this be the issue?</div><div> </div><div>thanks.</div><div> </div><div>rgds,</div><div>CL</div><div data-zbluepencil-ignore="true" style="" class="zmail_extra"><div> </div><div id="Zm-_Id_-Sgn1">---- On Mon, 09 Mar 2020 21:04:12 +0800 <b>Stéphane Mottelet <stephane.mottelet@utc.fr></b> wrote ----</div><div> </div><blockquote style="border-left: 1px solid rgb(204, 204, 204); padding-left: 6px; margin: 0px 0px 0px 5px;"><div>Maybe an inversion made in state-space could me more reliable ?<br /><br />S.<br /><br />Le 09/03/2020 à 13:36, <a target="_blank" href="mailto:sgougeon@free.fr">sgougeon@free.fr</a> a écrit :<br />> Hello Federico,<br />><br />> cond() and rcond() do not accept rationals, but the determinant of A is very close to 0:<br />> --> det(A)<br />> ans =<br />><br />> 3.573D-10<br />> ------------------------<br />> 0.0000027s² +7.433D-10s³<br />><br />> This likely explains that the inversion is not reliable.<br />><br />> Regards<br />> Samuel<br />> _______________________________________________<br />> users mailing list<br />> <a target="_blank" href="mailto:users@lists.scilab.org">users@lists.scilab.org</a><br />> <a target="_blank" href="https://antispam.utc.fr/proxy/1/c3RlcGhhbmUubW90dGVsZXRAdXRjLmZy/lists.scilab.org/mailman/listinfo/users">https://antispam.utc.fr/proxy/1/c3RlcGhhbmUubW90dGVsZXRAdXRjLmZy/lists.scilab.org/mailman/listinfo/users</a><br /><br />--<br />Stéphane Mottelet<br />Ingénieur de recherche<br />EA 4297 Transformations Intégrées de la Matière Renouvelable<br />Département Génie des Procédés Industriels<br />Sorbonne Universités - Université de Technologie de Compiègne<br />CS 60319, 60203 Compiègne cedex<br />Tel : +33(0)344234688<br /><a target="_blank" href="http://www.utc.fr/~mottelet">http://www.utc.fr/~mottelet</a><br /><br />_______________________________________________<br />users mailing list<br /><a target="_blank" href="mailto:users@lists.scilab.org">users@lists.scilab.org</a><br /><a target="_blank" href="http://lists.scilab.org/mailman/listinfo/users">http://lists.scilab.org/mailman/listinfo/users</a></div></blockquote></div><div> </div></div><br /> </html>