Thanks Rafael for the answer One explanation of the error is that I used a and b letter instead of aa and bb in your example; your code, if I change aa -> a and bb -> it fails again ... why ? (I do not understand)
EXPORT CONTROL : Cet email ne contient pas de données techniques This email does not contain technical data De : users [mailto:users-boun...@lists.scilab.org] De la part de Rafael Guerra Envoyé : jeudi 26 mai 2016 12:26 À : 'Users mailing list for Scilab' Objet : [EXTERNAL] Re: [Scilab-users] Vectorization issue Hi Paul, It seems that there may be some issues with the .*, .^ syntax and also the use of the same variable in different context (b). Editing the vectorization part of your code as follows: // using vectorization aa = [0:n]'; bb = ones(n,1); i = aa.*.bb; j = bb.*.aa; Km2 = zeros(n*(n+1),1); Km2 = %pi^6*((2*i+1).^2 .* j.^2).*((2*i+1).^2.*(b/2*d)^2 + j.^2) ; Km2 = (144*(b/d).^4)/ sum(Km2); Km2 = 1.2 + (nu/(1+nu))*Km2; k2 = 1/Km2 produces: k = 0.8333090 k2 = 0.8333333 A small difference. I did not check the formulas but it might be numerical error only. Regards, Rafael From: users [mailto:users-boun...@lists.scilab.org] On Behalf Of Carrico, Paul Sent: Thursday, May 26, 2016 11:30 AM To: International users mailing list for Scilab. (users@lists.scilab.org<mailto:users@lists.scilab.org>) <users@lists.scilab.org<mailto:users@lists.scilab.org>> Subject: [Scilab-users] Vectorization issue Dear I failed in using vectorization in the example immediately bellow; but I do not remember if it's possible : any advice ? Thanks Paul ###################################################################################### mode(0) n = 20 Km = 0; b = 100; d = 20; nu = 0.3; // using loops for i = 0 : n for j = 1 : n Km = Km + (144*(b/d)^4)/( %pi^6*(2*i+1)^2*j^2*((2*i+1)^2*(b/2*d)^2+j^2) ); end end Km = 1.2 + (nu/(1+nu))*Km k = 1/Km // using vectorization a = [0:n]'; b = ones(n,1); i = a.*.b; j = b.*.a; Km2 = zeros(n*(n+1),1); //toto = i. *j Km2 = ( %pi.^6*((2*i+1).^2. * j.^2)*((2*. i+1).^2*(b/2*d).^2 + j^2) ) Km2 = (144*(b/d).^4)/ Km2 Km2 = 1.2 + (nu/(1+nu))*Km2 k2 = 1/Km2 EXPORT CONTROL : Cet email ne contient pas de données techniques This email does not contain technical data
_______________________________________________ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users
