# How do I plot the dynamics of agents influencing each other?

2 views (last 30 days)
DB on 22 Nov 2020
Answered: Sindhu Karri on 25 Nov 2020
Hi,
I want to plot the influence of agents on each other in a graph. For this example, I have three agents :
k=1
x1(k)=10;
x2(k)=20;
x3(k)=30;
With k being a time step. The influence on each other will be calculated with factors in Matrix A:
A=[a11 a12 a13; a21 a22 a23; a31 a32 a33];
a11=0.1;
a12=0.2;
a13=0.3;
a21=0.4;
a22=0.5;
a23=0.6;
a31=0.7;
a32=0.8;
a33=0.9;
I want to model the influences with:
n=10;
for k=1:n;
x(k)=[x1(k);x2(k);x3(k)];
x(k+1)=A*x(k)
plot(k,x(k))
end
However, I get these errors:
Unable to perform assignment because the left and right sides have a different number of elements.
Error in impexss (line 23)
x(k)=[x1(k);x2(k);x3(k)];
This is probably because x(k) increases in size, but I don't want it to.
Ultimately I want to see something like this in matrix form:
x1(k+1)=a11*x1(k)+a12*x2(k)+a13*x3(k);
x2(k+1)=a21*x1(k)+a22*x2(k)+a23*x3(k);
x3(k+1)=a31*x1(k)+a32*x2(k)+a33*x3(k);
x1(k+2)=a11*x1(k+1)+a12*x2(k+1)+a13*x3(k+1)
x2(k+2)=a21*x1(k+1)+a22*x2(k+1)+a23*x3(k+1)
x3(k+2)=a31*x1(k+1)+a32*x2(k+1)+a33*x3(k+1)
But I cannot figure how to code this. I also want to plot this. Could anyone please help?

Sindhu Karri on 25 Nov 2020
Hii David,
Hope below attached code helps you
x1(1)=10;
x2(1)=20;
x3(1)=30;
A=[0.1,0.2,0.3;0.4,0.5,0.6;0.7,0.8,0.9];%a11,a12,a13,a21,a22,a23,a31,a32,a33
n=10;
for k=1:n
x1(k+1)=A(1,1)*x1(k)+A(1,2)*x2(k)+A(1,3)*x3(k);
x2(k+1)=A(2,1)*x1(k)+A(2,2)*x2(k)+A(2,3)*x3(k);
x3(k+1)=A(3,1)*x1(k)+A(3,2)*x2(k)+A(3,3)*x3(k);
end
plot(x3)%plotting

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