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clear;
clc;
close;
disp("When the eigen values are complex, then the fixed point is either :")
disp("1. Center, or")
disp("2. Spiral.")
function xd=linear524(t,x)
xd(1)=0*x(1)+x(2); //x(dot); x(2) means y.
xd(2)=-4*x(1)+0*x(2); //y(dot); x(1) means x.;
endfunction
bound=[-14,-25,14,25]; //Bounds of x-axis and y-axis as [xmin ymin xmax ymax], change them according to your needs.
nrect=10; //increase it to get more number of curves, i.e. more information will be available.
set(gca(),"auto_clear","off") //hold on
x=linspace(bound(1),bound(3),nrect);
y=linspace(bound(2),bound(4),nrect);
x0=[];
for i=1:10
x0=[x(i);y(i)];
t0=0;
t=0:0.01:3000;
xout=ode(x0,t0,t,linear524);
plot2d(xout(1,:),xout(2,:));
end
xtitle('Phase Portrait','x-axis ( x )','y-axis ( y )')
figure
function xd=linear5242(t,x)
xd(1)=-x(1)-x(2); //x(dot); x(2) means y.
xd(2)=4*x(1)-x(2); //y(dot); x(1) means x.;
endfunction
bound=[-14,-25,14,25]; //Bounds of x-axis and y-axis as [xmin ymin xmax ymax], change them according to your needs.
nrect=10; //increase it to get more number of curves, i.e. more information will be available.
set(gca(),"auto_clear","off") //hold on
x=linspace(bound(1),bound(3),nrect);
y=linspace(bound(2),bound(4),nrect);
x0=[];
for i=1:10
x0=[x(i);y(i)];
t0=0;
t=0:0.01:3000;
xout=ode(x0,t0,t,linear5242);
plot2d(xout(1,:),xout(2,:));
end
xtitle('Phase Portrait','x-axis ( x )','y-axis ( y )')
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