Can Matlab create Laplace Transfer equations using symbolic math.

I would like to create a program to model the Laplace transform of a circuit using the MATLAB symbolic tool box. I have written the following code:

clc 
clear all
close
syms s I1 I2 I3 Vs
Z = [(2*s+2) -(2*s+1) -1
       -(2*s+1) (9*s+1) -4*s
       -1 -4*s (4*s+1+s^-1)]; 
V = [Vs;0;0]; 
I = Z\V
I2 = I(2)
Gs = sym('I2*3*s/Vs')

G3 = sym('(Vs*(8*s^3 + 10*s^2 + 3*s + 1))/(24*s^4 + 30*s^3 + 17*s^2 + 16*s + 1)*3*s/Vs')

The line beginning with Gs does not result in an output. The line beginning with G3 will deliver a usable output when I copy and past the output from the I2 output.

Can code be written to symbolically calculate a Laplace output of all possible combinations of voltage or current in a circuit?

Answer 1

[jerry]

I made the following change to my coding:

clc 
clear all
close
syms s I1 I2 I3 Vs
Z = [(2*s+2) -(2*s+1) -1
       -(2*s+1) (9*s+1) -4*s
       -1 -4*s (4*s+1+s^-1)]; 
V = [Vs;0;0]; 
I = Z\V
I2 = I(2)
char(I(2))
Gs = sym('(char(I(2))*3*s)/Vs')

G3 = sym('(Vs*(8*s^3 + 10*s^2 + 3*s + 1))/(24*s^4 + 30*s^3 + 17*s^2 + 16*s + 1)*3*s/Vs')

MATLAB gave the following answer to Gs:

Gs = (3*s*char(i))/Vs

Notice the "I" has been changed to "i". I've never seen this phenomena before and I'm still as far away as I was before.