何必手算？MATLAB求解线性方程组（以回路电流法为例）|Matlab符号计算

clc

clear

close all

syms R1 R2 R3 R4 R5 R6 Us1 Us5

syms I11 I12 I13

[R1, R2, R3, R4, R5, R6, Us1, Us5] = deal(1, 1, 1, 2, 2, 2, 4, 2);

equ = [R1*I11+Us1+R6*(I11-I13)+R5*(I11+I12-I13)-Us5+R4*(I11+I12)==0;...

  R2*I12+R5*(I12+I11-I13)-Us5+R4*(I11+I12)==0;...

  R6*(I13-I11)+R3*I13+Us5+R5*(I13-I11-I12)==0]

f = solve(equ, [I11, I12, I13]);

I11 = double(f.I11)

I12 = double(f.I12)

I13 = double(f.I13)

A = [7 4 -4;4 5 -2;-4 -2 5];

B = [-2; 2; -2];

g = A\B