Figure 's issue

Hi everyone. I wrote the code below for plotting a 2d figure (ct-h) but it doesn't work; I mean it doesn't show any figure. Could you please tell me what is the problem, and how can I solve it?

Thanks in advance for any help.

vplc=0.16;
delta=0.1;
Ktau=0.045;
Kc=0.1; 
K=0.0075;
Kp=0.15;
gamma=5.5;
kb=0.4;
vss=0.044;
alpha0=delta*6.81e-6/(0.002);
alpha1=delta*2.27e-5/(0.002);
Ke=7;
Vs=0.002;
ks=0.1;
Kf=0.18;
kplc=0.055;
ki=2;

[ct]=meshgrid(0.0001:0.05:30);

x=(((2.*Vs.*K.*gamma.^2.*ct.^2)./(vss))+((2.*alpha0.*ks.^2)./(vss))+((2.*Ke.^4.*ks.^2.*alpha1)./(vss.*(Ke.^4+(gamma.*ct).^4))));
p=(vplc./ki).*(x./((kplc).^2+x));
A=(-(vss.*x)./(ks.^2))+((Vs.*K.*gamma.^2.*ct.^2)./(ks.^2))+alpha0+alpha1.*((Ke.^4)./(Ke.^4+(gamma.*ct).^4));
h=-(0.4.*A.*((Kc.^4).*(Kp.^2))./((p.^2.*x.^2.*gamma.*ct.*Kf)));

plot(ct,h); 

Answer 1

[Walter Roberson]

[ct]=meshgrid(0.0001:0.05:30);

is treated the same way as if you had used

[ct, ~]=meshgrid(0.0001:0.05:30, 0.0001:0.05:30);

It creates a 600 x 600 grid that is just a lot of repeats of the same values. So you end up plotting 600 lines.

I suggest you use semilogy instead of plot()

[M]

Thanks for the answer..I again try with what you suggested but it doesn't work actually..I really don't know whta is the problem that doesn't show any thing

[Torsten]

ct = 0.0001:0.05:30

instead of

[ct]=meshgrid(0.0001:0.05:30);

and

semilogy(ct,h)

instead of

plot(ct,h)

[M]

Many thanks it works

[M]

With "plot(ct,h)" also worked and gave me the figure that I expected, so the problem was defining ct that shouldn't use "meshgrid".

[Torsten]

With "plot(ct,h)" also worked and gave me the figure that I expected

I only see one small jump at 0 and everything else on the zero level

vplc=0.16;
delta=0.1;
Ktau=0.045;
Kc=0.1; 
K=0.0075;
Kp=0.15;
gamma=5.5;
kb=0.4;
vss=0.044;
alpha0=delta*6.81e-6/(0.002);
alpha1=delta*2.27e-5/(0.002);
Ke=7;
Vs=0.002;
ks=0.1;
Kf=0.18;
kplc=0.055;
ki=2;
ct=0.0001:0.05:2;
x=(((2.*Vs.*K.*gamma.^2.*ct.^2)./(vss))+((2.*alpha0.*ks.^2)./(vss))+((2.*Ke.^4.*ks.^2.*alpha1)./(vss.*(Ke.^4+(gamma.*ct).^4))));
p=(vplc./ki).*(x./((kplc).^2+x));
A=(-(vss.*x)./(ks.^2))+((Vs.*K.*gamma.^2.*ct.^2)./(ks.^2))+alpha0+alpha1.*((Ke.^4)./(Ke.^4+(gamma.*ct).^4));
h=-(0.4.*A.*((Kc.^4).*(Kp.^2))./((p.^2.*x.^2.*gamma.*ct.*Kf)));
plot(ct,h); 

whereas the semilogy option gives a good resolution of the different scales:

vplc=0.16;
delta=0.1;
Ktau=0.045;
Kc=0.1; 
K=0.0075;
Kp=0.15;
gamma=5.5;
kb=0.4;
vss=0.044;
alpha0=delta*6.81e-6/(0.002);
alpha1=delta*2.27e-5/(0.002);
Ke=7;
Vs=0.002;
ks=0.1;
Kf=0.18;
kplc=0.055;
ki=2;
ct=0.0001:0.05:2;
x=(((2.*Vs.*K.*gamma.^2.*ct.^2)./(vss))+((2.*alpha0.*ks.^2)./(vss))+((2.*Ke.^4.*ks.^2.*alpha1)./(vss.*(Ke.^4+(gamma.*ct).^4))));
p=(vplc./ki).*(x./((kplc).^2+x));
A=(-(vss.*x)./(ks.^2))+((Vs.*K.*gamma.^2.*ct.^2)./(ks.^2))+alpha0+alpha1.*((Ke.^4)./(Ke.^4+(gamma.*ct).^4));
h=-(0.4.*A.*((Kc.^4).*(Kp.^2))./((p.^2.*x.^2.*gamma.*ct.*Kf)));
semilogy(ct,h); 

[M]

Yeah, that's true, and I understood what you said, but the point is that only this part ct=[0,2] and h=[0,1] is important for me, and with "plot", it seems to work better (at least for this case).