# [Scilab-users] Problems with Bode and Bode asymptotic

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## [Scilab-users] Problems with Bode and Bode asymptotic

 I don't succeed in using the Bode plots facilities. (See script below). - on fig 1 and 2 one sees a shift between the true and the asymptotic Bode plot _ on fig 3 one sees a strange plot corresponding to the second argument of frequency bounds. Do you have any idea ? Thank in advance. Emmanuel //------------------------------------------------------------------------------------------------------------- // xdel(winsid()); f1 = 100; w1 = 2*%pi*f1; tau1 = 1/w1; H1 = 10/(1 + tau1*%s); // order 1 system S1 = syslin('c',H1); scf(1); bode(S1);//,[0.001,10000]); bode_asymp(S1); xtitle('Order one'); //xs2pdf(1,'order1bode'); m = .125;//sqrt(2)/4; wn = w1; H2 = 10/(1 + 2*m*%s/wn + %s^2/wn^2); // order 2 system S2 = syslin('c',H2); scf(2); bode(S2,[.01,1e4]); bode_asymp(S2); xtitle('Order two'); //xs2pdf(2,'order2bode'); scf(3); bode(S1,[0.01,1000]); _______________________________________________ users mailing list [hidden email] http://lists.scilab.org/mailman/listinfo/users
 Hello,   Noting that bode_asymp() takes (rad/s) inputs and that the bracketed syntax [ , ] in Scilab’s help file means optional inputs, please check this:   `// START OF CODE` `xdel(winsid());` `fmin = 1e-2;` `fmax = 1e4;` `wmin = 2*%pi*fmin;` `wmax = 2*%pi*fmax;` ` ` `f1 = 100;` `w1 = 2*%pi*f1;` `tau1 = 1/w1;` `H1 = 10/(1 + tau1*%s); // order 1 system` `S1 = syslin('c',H1);` `scf(1);` `bode(S1,fmin,fmax);` `bode_asymp(S1,wmin,wmax);` `xtitle('Order one');` ` ` `m = .125;//sqrt(2)/4;` `wn = w1;` `H2 = 10/(1 + 2*m*%s/wn + %s^2/wn^2); // order 2 system` `S2 = syslin('c',H2);` `scf(2);` `bode(S2,fmin,fmax);  // ` `bode_asymp(S2,wmin,wmax);` `xtitle('Order two');` ` ` `scf(3);` `bode(S1,fmin,fmax);` `// END OF CODE`   Regards, Rafael _______________________________________________ users mailing list [hidden email] http://lists.scilab.org/mailman/listinfo/users