Undefined function or variable

t=1;
R1=1;
R0=10;
w=(0.001:0.001:1000)
log10w=log10(w)
a1=0.25;
a2=0.5;
a3=0.75;
a4=1;
c1=cos((a1*pi)/2);
s1=sin((a1*pi)/2);

ModZ1=sqrt((R1^2.*(w*t)).^2*a1+2*c1*R0*R1.*(w*t).^a1+R0^2)./(1+2*c1.*(w*t).^a1+(w*t).^2*a1);

c2=cos((a2*pi)/2);
s2=sin((a2*pi)/2);

ModZ2=sqrt((R1^2.*(w*t)).^2*a2+2*c1*R0*R1.*(w*t).^a2+R0^2)./(1+2*c1.*(w*t).^a2+(w*t).^2*a2);

c3=cos((a3*pi)/2);
s3=sin((a3*pi)/2);

ModZ3=sqrt((R1^2.*(w*t)).^2*a3+2*c1*R0*R1.*(w*t).^a3+R0^2)./(1+2*c1.*(w*t).^a3+(w*t).^2*a3);

c4=cos((a4*pi)/2);
s4=sin((a4*pi)/2);

ModZ4=sqrt((R1^2.*(w*t)).^2*a4+2*c1*R0*R1.*(w*t).^a4+R0^2)./(1+2*c1.*(w*t).^a4+(w*t).^2*a4);

plot(log10w,ModZ1,'k')
hold on
plot(log10w,ModZ2,'y');
plot(log10w,ModZ3,'b');
plot(log10w,ModZ4,'m');

xlabel('log10w');
ylabel('|Z|')

When I press run it says "undefined function of variable "modulus" ?

[Madara Hettigama]

Basically I need a graphical plot - i'm not sure where the error is

[per isakson]

Your code runs and creates a plot without problems on R2018b.

Run

dbstop if error 

before running your script

And see

• Debug a MATLAB Program and
• Examine Values While Debugging

[Walter Roberson]

I do not encounter any difficulty in running that code. Other than the fact that you really really should put a semi-colon on the end of the assignments to w and log10w because your vectors are quite long.

Answer 1

[Jeremy]

Your script runs for me as-is

[Madara Hettigama]

Im trying to plot in 4d so i need the graph but it keeps coming up with that message

[Walter Roberson]

clear all
dbstop if error

then run your code, and tell us exactly where it stops. The output of

dbstack

would help.

[Madara Hettigama]

It's fine now I think- I clicked run section and graph came up, thank you.