how to substitute sym variables in jacobian matrix with numeric values?

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syms x y z
u = -Iscr + Iph - (x * ((exp((Iscr*y)/(n*Vth)))-1)) ...
- ((Iscr*y)/z);
v = Iph - (x * ((exp((Vocr)/(n*Vth)))-1)) - ((Vocr)/z);
w = -Im + Iph - (x * ((exp((Vm + Im*y)/(n*Vth)))-1))...
- ((Vm + (Im*y))/z);
a= jacobian([u;v;w],[x,y,z])
j=subs(a,[x,y,z],[xo,yo,zo]) %% This doesn't work, please explain why and also the alternative to this.

Answers (1)

Devineni Aslesha
Devineni Aslesha on 24 Feb 2020
The ‘subs’ function works as expected. Please find the code shown below.
Iscr = 1;
Iph = 2;
Vth = 5;
n = 4;
Vocr = 3;
Im = 2;
Vm = 5;
syms x y z
u = -Iscr + Iph - (x * ((exp((Iscr*y)/(n*Vth)))-1)) ...
- ((Iscr*y)/z);
v = Iph - (x * ((exp((Vocr)/(n*Vth)))-1)) - ((Vocr)/z);
w = -Im + Iph - (x * ((exp((Vm + Im*y)/(n*Vth)))-1))...
- ((Vm + (Im*y))/z);
a = jacobian([u;v;w],[x,y,z]);
j = subs(a,[x,y,z],[1,2,3]);

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