help in matlab

NOW · Dec 24, 2012

i have a problem here
in making a project for some transmition line i made code in matlab which is down and the matlabe dos not run it ,why??????

f=0:10e9/201:10e9;
for t=1:202
f0=5e9;
Z0=50;
w=pi*f(t)/(2*f0);
a=cos(w);
b=j*Z0*sin(w);
c=j*sin(w)/Z0;
d=cos(w);
a1=cos(w);
b1=j*Z0*sin(w)/sqrt(2);
c1=j*sqrt(2)*sin(w)/Z0;
d1=cos(w);
x0=[1 0 0 0 0 0 a1 c1]';
x1=[0 -1 0 0 0 0 0 0]';
x2=[(a*Z0)+b (c*Z0)+d -Z0 0 0 0 0 0]';
x3=[-a*Z0 -c*Z0 Z0 -1 0 0 0 0]';
x4=[0 0 (a1*Z0)+b1 (c1*Z0)+d1 -Z0 0 0 0]';
x5=[0 0 0 0 -a*Z0 (Z0*c)+1 -Z0 0]';
x6=[0 0 a1*Z0 Z0 b-Z0 d 0 0]';
x7=[0 0 0 0 0 0 0 1]';
x8=[0 0 0 0 a*Z0 -c*Z0 Z0-b1 -d]';
y=[x1 x2 x3 x4 x5 x6 x7 x8];
y1=[x0 x2 x3 x4 x5 x6 x7 x8];
y2=[x1 x0 x3 x4 x5 x6 x7 x8];
y3=[x1 x2 x0 x4 x5 x6 x7 x8];
y4=[x1 x2 x3 x0 x5 x6 x7 x8];
y5=[x1 x2 x3 x4 x0 x6 x7 x8];
y6=[x1 x2 x3 x4 x5 x0 x7 x8];
y7=[x1 x2 x3 x4 x5 x6 x0 x8];
y8=[x1 x2 x3 x4 x5 x6 x7 x0];
ia1=det(y1)/det(y);
ia2=det(y2)/det(y);
ib1=det(y3)/det(y);
ib2=det(y4)/det(y);
ic1=det(y5)/det(y);
ic2=det(y6)/det(y);
id1=det(y7)/det(y);
id2=det(y8)/det(y);
i1=ia1+id1;
i2=ia2+ib1;
i3=ib2+ic2;
i4=id2-ic1;
Zin=1/i1;

G=(Zin-Z0)/(Zin+Z0);

Gin=sqrt(real(G)^2+imag(G)^2);
p1=(1-Gin^2)/(2*Z0);
p2=i2^2*Z0;
p3=i3^2*Z0;
p4=i4^2*Z0;

GdB=10*log(Gin);
end

plot(f,GdB);

MrChips · Dec 24, 2012

Yeah, I can see why.

panic mode · Dec 24, 2012

you are going through loop to calculate something for many points, but result is stored in ONE point only. try to replace third last line to

GdB(t)=10*log(Gin);

if you are to plot something, it has to be a vector or array

NOW · Dec 24, 2012

sounds that u have it......

NOW · Dec 24, 2012

i dont understand why i have:
Warning: Divide by zero.

panic mode · Dec 24, 2012

if you have an error, you need to check what line of code causes it. matlab gives quite detailed feedback. i just run this and it worked for me:

Rich (BB code):

f=0:10e9/201:10e9;

f0=5e9; // there is no point to place this inside the loop 
Z0=50;
    
for t=1:202
    w=pi*f(t)/(2*f0);
    a=cos(w);
    b=j*Z0*sin(w);
    c=j*sin(w)/Z0;
    d=cos(w);
    a1=cos(w);
    b1=j*Z0*sin(w)/sqrt(2);
    c1=j*sqrt(2)*sin(w)/Z0;
    d1=cos(w);
    x0=[1 0 0 0 0 0 a1 c1]';
    x1=[0 -1 0 0 0 0 0 0]';
    x2=[(a*Z0)+b (c*Z0)+d -Z0 0 0 0 0 0]';
    x3=[-a*Z0 -c*Z0 Z0 -1 0 0 0 0]';
    x4=[0 0 (a1*Z0)+b1 (c1*Z0)+d1 -Z0 0 0 0]';
    x5=[0 0 0 0 -a*Z0 (Z0*c)+1 -Z0 0]';
    x6=[0 0 a1*Z0 Z0 b-Z0 d 0 0]';
    x7=[0 0 0 0 0 0 0 1]';
    x8=[0 0 0 0 a*Z0 -c*Z0 Z0-b1 -d]';
    y=[x1 x2 x3 x4 x5 x6 x7 x8];
    y1=[x0 x2 x3 x4 x5 x6 x7 x8];
    y2=[x1 x0 x3 x4 x5 x6 x7 x8];
    y3=[x1 x2 x0 x4 x5 x6 x7 x8];
    y4=[x1 x2 x3 x0 x5 x6 x7 x8];
    y5=[x1 x2 x3 x4 x0 x6 x7 x8];
    y6=[x1 x2 x3 x4 x5 x0 x7 x8];
    y7=[x1 x2 x3 x4 x5 x6 x0 x8];
    y8=[x1 x2 x3 x4 x5 x6 x7 x0];
    ia1=det(y1)/det(y);
    ia2=det(y2)/det(y);
    ib1=det(y3)/det(y);
    ib2=det(y4)/det(y);
    ic1=det(y5)/det(y);
    ic2=det(y6)/det(y);
    id1=det(y7)/det(y);
    id2=det(y8)/det(y);
    i1=ia1+id1;
    i2=ia2+ib1;
    i3=ib2+ic2;
    i4=id2-ic1;
    Zin=1/i1;


    G=(Zin-Z0)/(Zin+Z0);

    Gin=sqrt(real(G)^2+imag(G)^2);
    p1=(1-Gin^2)/(2*Z0);
    p2=i2^2*Z0;
    p3=i3^2*Z0;
    p4=i4^2*Z0;

    GdB(t)=10*log(Gin); // this is the only true change (made GdB an array)
end

plot(f,GdB);

panic mode · Dec 24, 2012

also put this as first line of any matlab script:

Rich (BB code):

clc; clear all; close all;

so every time you run some code, you get clean sheet. you can use break points to stop code at particular places and narrow down what causes issues, check variables etc.

NOW · Dec 24, 2012

panic mode said:

if you have an error, you need to check what line of code causes it. matlab gives quite detailed feedback. i just run this and it worked for me:

Rich (BB code):

f=0:10e9/201:10e9;

f0=5e9; // there is no point to place this inside the loop 
Z0=50;
    
for t=1:202
    w=pi*f(t)/(2*f0);
    a=cos(w);
    b=j*Z0*sin(w);
    c=j*sin(w)/Z0;
    d=cos(w);
    a1=cos(w);
    b1=j*Z0*sin(w)/sqrt(2);
    c1=j*sqrt(2)*sin(w)/Z0;
    d1=cos(w);
    x0=[1 0 0 0 0 0 a1 c1]';
    x1=[0 -1 0 0 0 0 0 0]';
    x2=[(a*Z0)+b (c*Z0)+d -Z0 0 0 0 0 0]';
    x3=[-a*Z0 -c*Z0 Z0 -1 0 0 0 0]';
    x4=[0 0 (a1*Z0)+b1 (c1*Z0)+d1 -Z0 0 0 0]';
    x5=[0 0 0 0 -a*Z0 (Z0*c)+1 -Z0 0]';
    x6=[0 0 a1*Z0 Z0 b-Z0 d 0 0]';
    x7=[0 0 0 0 0 0 0 1]';
    x8=[0 0 0 0 a*Z0 -c*Z0 Z0-b1 -d]';
    y=[x1 x2 x3 x4 x5 x6 x7 x8];
    y1=[x0 x2 x3 x4 x5 x6 x7 x8];
    y2=[x1 x0 x3 x4 x5 x6 x7 x8];
    y3=[x1 x2 x0 x4 x5 x6 x7 x8];
    y4=[x1 x2 x3 x0 x5 x6 x7 x8];
    y5=[x1 x2 x3 x4 x0 x6 x7 x8];
    y6=[x1 x2 x3 x4 x5 x0 x7 x8];
    y7=[x1 x2 x3 x4 x5 x6 x0 x8];
    y8=[x1 x2 x3 x4 x5 x6 x7 x0];
    ia1=det(y1)/det(y);
    ia2=det(y2)/det(y);
    ib1=det(y3)/det(y);
    ib2=det(y4)/det(y);
    ic1=det(y5)/det(y);
    ic2=det(y6)/det(y);
    id1=det(y7)/det(y);
    id2=det(y8)/det(y);
    i1=ia1+id1;
    i2=ia2+ib1;
    i3=ib2+ic2;
    i4=id2-ic1;
    Zin=1/i1;


    G=(Zin-Z0)/(Zin+Z0);

    Gin=sqrt(real(G)^2+imag(G)^2);
    p1=(1-Gin^2)/(2*Z0);
    p2=i2^2*Z0;
    p3=i3^2*Z0;
    p4=i4^2*Z0;

    GdB(t)=10*log(Gin); // this is the only true change (made GdB an array)
end

plot(f,GdB);

but in the command windows gives me an error....!!

panic mode · Dec 24, 2012

replace // with % or remove comments.

panic mode · Dec 24, 2012

Rich (BB code):

clc; clear all; close all;

f=0:10e9/201:10e9;
f0=5e9;
Z0=50;
    
for t=1:202
    w=pi*f(t)/(2*f0);
    a=cos(w);
    b=j*Z0*sin(w);
    c=j*sin(w)/Z0;
    d=cos(w);
    a1=cos(w);
    b1=j*Z0*sin(w)/sqrt(2);
    c1=j*sqrt(2)*sin(w)/Z0;
    d1=cos(w);
    x0=[1 0 0 0 0 0 a1 c1]';
    x1=[0 -1 0 0 0 0 0 0]';
    x2=[(a*Z0)+b (c*Z0)+d -Z0 0 0 0 0 0]';
    x3=[-a*Z0 -c*Z0 Z0 -1 0 0 0 0]';
    x4=[0 0 (a1*Z0)+b1 (c1*Z0)+d1 -Z0 0 0 0]';
    x5=[0 0 0 0 -a*Z0 (Z0*c)+1 -Z0 0]';
    x6=[0 0 a1*Z0 Z0 b-Z0 d 0 0]';
    x7=[0 0 0 0 0 0 0 1]';
    x8=[0 0 0 0 a*Z0 -c*Z0 Z0-b1 -d]';
    y=[x1 x2 x3 x4 x5 x6 x7 x8];
    y1=[x0 x2 x3 x4 x5 x6 x7 x8];
    y2=[x1 x0 x3 x4 x5 x6 x7 x8];
    y3=[x1 x2 x0 x4 x5 x6 x7 x8];
    y4=[x1 x2 x3 x0 x5 x6 x7 x8];
    y5=[x1 x2 x3 x4 x0 x6 x7 x8];
    y6=[x1 x2 x3 x4 x5 x0 x7 x8];
    y7=[x1 x2 x3 x4 x5 x6 x0 x8];
    y8=[x1 x2 x3 x4 x5 x6 x7 x0];
    ia1=det(y1)/det(y);
    ia2=det(y2)/det(y);
    ib1=det(y3)/det(y);
    ib2=det(y4)/det(y);
    ic1=det(y5)/det(y);
    ic2=det(y6)/det(y);
    id1=det(y7)/det(y);
    id2=det(y8)/det(y);
    i1=ia1+id1;
    i2=ia2+ib1;
    i3=ib2+ic2;
    i4=id2-ic1;
    Zin=1/i1;


    G=(Zin-Z0)/(Zin+Z0);

    Gin=sqrt(real(G)^2+imag(G)^2);
    p1=(1-Gin^2)/(2*Z0);
    p2=i2^2*Z0;
    p3=i3^2*Z0;
    p4=i4^2*Z0;

    GdB(t)=10*log(Gin);
end

plot(f,GdB);

NOW · Dec 24, 2012

i mean :Warning: Divide by zero.

panic mode · Dec 24, 2012

i don't know what are you talking about. i just run the code and posted screenshot. and i just repeated it using code in post #10. can you at least tell where you get the warning? what line of code? how are you testing it? are you typing the code in the command window or executing it as a script?

just open matlab, go to menu File, New, Script and paste code from post #10. then press F5 to run it. if prompted save it anywhere and choose "Change Folder". that's it.

NOW · Dec 24, 2012

this what i have:

> In YESm at 33
Warning: Divide by zero.
> In YESm at 34
Warning: Divide by zero.
> In YESm at 35
Warning: Divide by zero.
> In YESm at 36
Warning: Divide by zero.
> In YESm at 37
Warning: Divide by zero.
> In YESm at 38
Warning: Divide by zero.
> In YESm at 39
Warning: Divide by zero.
> In YESm at 40
Warning: Imaginary parts of complex X and/or Y arguments ignored.
> In YESm at 61
Warning: Divide by zero.
> In YESm at 33
Warning: Divide by zero.
> In YESm at 34
Warning: Divide by zero.
> In YESm at 35
Warning: Divide by zero.
> In YESm at 36
Warning: Divide by zero.
> In YESm at 37
Warning: Divide by zero.
> In YESm at 38
Warning: Divide by zero.
> In YESm at 39
Warning: Divide by zero.
> In YESm at 40
Warning: Imaginary parts of complex X and/or Y arguments ignored.
> In YESm at 61
>>

Thread starter	Similar threads	Forum	Replies	Date
R	Seismic Shake Table Control Board Refurbishment Help	Technical Repair	0	Oct 1, 2025
	How to capture live running traces from MSO7104B oscilloscope with the help of MATLAB without any delay?	Test & Measurement	2	Jul 16, 2023
	I need help with following MATLAB Question	Homework Help	2	Dec 7, 2022
S	Machine learning logistic regression matlab code help	Homework Help	3	Apr 18, 2021
R	matlab short matrix help	Homework Help	4	May 15, 2020

help in matlab

Join our Engineering Community! Sign-in with:

help in matlab

NOW

MrChips

panic mode

NOW

NOW

panic mode

Attachments

panic mode

NOW

panic mode

panic mode

NOW

panic mode

NOW

You May Also Like

Boost the Power Delivery Potential of USB-C Ports with Protection Switches

Rohm Shoots Out 17 New Op Amps to Its High-Performance Portfolio

ADI Quietly Rolls Out 8- and 16-Channel, Easy Drive Multiplexed SAR ADCs

Preventing Runt Pulses in Phase/Frequency Detectors