How can I write a code for cicuits?

I am asked to Write a program in MATLAB to analyze a circuit. The circuit contains of n Resistors, n/2 capacitors, n/2 coils and an AC voltage source in the form of V Vm wt = + cos( )  .

The following requirements should be fulfilled

1. The number of resistances, n, has to be even number.

2. The minimum value for n is 2.

3. If the number of resistances is n, the number of coils must be n/2 and the number of capacitors must be n/2. The user will be prompted to enter the correct number if it is different from n/2

4. The values of all resistors, coils and capacitors must be real and positive

Please help me with the code.. I'm dying trying to find videos and tutorials

Sample example 1 (note: The red colour represents the data entered by the user) Enter the resistance values in ohm, [R1...Rn]=[10 30 20] The number of resistances should be even. Reenter values of the two resistances in Ohm, [R1...Rn]=[10 20 40 100] ==============================================================================

Enter the capacitance values in Farads, [C1...Cn/2]=[0.01 0.02 0.04]

The number of capacitors should be 2, 1/2 number of resistances Enter the capacitance values in Farads, [C1...Cn/2]=[0.01 0.02] ==============================================================================

Enter the inductance values in Henry, [L1...Ln/2]=[0.3 0.2] ==============================================================================

Enter the amplitude of the voltage source in volt, Vmag=10

Enter the phase of the voltage source in degree, Vphase=0

Enter the frequency of the voltage source in rad/s, Freq=100

[darova]

The question is too long. Do you have any specific problems? Where are your attempts?

[Mariam Al Zarouni]

I need a code where I can ask the user to enter a random but EVEN number of resistor values. For example, if the user writes [ 5 1 3] , the the output would say " no , the number of resistors must be even,re-write it again." and the user will re-write the values for example [ 5 1 3 8] and then the loop will continue in that case and so on for the rest of the conditions listed above. Hope you can help.

[darova]

You need to use input function to ask user for data

mod function can help your to check if number is odd or even

So what kind of help do you need? Here is input and here mod

[Mariam Al Zarouni]

Thank you so much. I'll start writing my code and i'll tell you if i face any problems later on. BUT STILL THANK YOU VERY MUCH for your quick reply.

[darova]

You are always welcome

[Mariam Al Zarouni]

I want to write a while loop code where i can ask my user to enter an infinite but EVEN number of values . Theses values must be real and positive. If the values enetered by the user satisfy my condition, it will end the the loop.

My attemtps where many and they all didn't end well , most ended with a red message from matlab:)

Hope you can help me with the code

clear all ;
close all;

equation=false;
while equation==false
    Resistors=input(' Enter values of two resistances in ohm [R1 R2]= '); % to enter tha values of the resistors
    Total=length(Resistors);
    m= Resistor
    if mod(m,2) == 0
        [row,column]=size(Resistors);% matrix of the resistors
        if isreal(Resistors) && row==1 && column>=2 % this is to make sure the values are real and the matrix is one row and two columns
            for number=1:Total
                if Resistors(number)>0 % value of the resistor is positive or otherwise
                    equation=true;
                elseif Resistors(number)<=0
                    equation=false;                    
                    break;
                end
            end
        end
    end
    
    if equation==false
        disp(' invalid numbers .... please enter valid numbers')
    end
end
disp ('===================================================================')

[John D'Errico]

You want to enter an infinite number of resistors? That will not take a long time to run?

Until you learn to write code carefully and to debug it, you won't get far writing code. I'm sorry, but this is true.

Here, for example, you most immediate error is that you enter the resistors in the variable Resistors, yet then you use the variable Resistor.

While that is most likely just a typo, MATLAB does not know this.

Computers cannot read your mind. Perhaps the indicated error was not a mistake, but intentional. They try to do what you tell them to do, and then if something happens that is a problem, they return an error message indicating what it sees as the problem.

So you need to learn to read the error message, then look at your code and fix it. Sometimes that is best done using the debugger to track down your problem. Here the error message would have said something about the existence of a variable or function named Resistor. Since you apparently wanted to use the variable Resistors, you should have seen the problem immediately.

I have a funny feeling that your code has at least two other errors in it. But learning to use the debugger will help you greatly.

[Mariam Al Zarouni]

umm i really didn't get younor your suggestion. If you could either be clearer or teach me how to write a while loop code with "and" conditions..thank you though

[darova]

I changed this part of your code and it works ok

[John D'Errico]

How much more clear must I be? You typed the variable named Resistors incorrectly, calling it Resistor, WITHOUT an s at the end.

That will generate an error. Your code will then fail to run.

How should you fix it? Edit the code. Fix the typing error. Then try to run the code again, perhaps fixing the next errors until you have code that works and does what you wish it to do.

[Mariam Al Zarouni]

I can't thank you enough Darova for you help with me. May god bless you soul.

[darova]

I voted for your question for your gratitude

[Mariam Al Zarouni]

Sorry for disturbing you again, but if i wanted to specify things for example if the number of values isn't even i want a sentence to be displayed saying "rewrite the values aking sure their number is even" and if the numbers entered by the user are complex and negative which is opposite to my code i also want a similar message to show.. so basically for each condition i want a message to be displayed.. I tried playing around with the end of the code and it got me somewhere but not exactly my wish.. could you give me your tips, guidience, and little bit help?

clear all ;
close all;
equation=false;
while equation==false
    Resistors=input(' Enter the resistance values in ohm, [R1...Rn]= '); % to enter tha values of the resistors
    V=length(Resistors);
    
    if mod(V,2) == 0
        [row,column]=size(Resistors);% matrix of the resistors
        if isreal(Resistors) && row==1 && column>=2 % this is to make sure the values are real and the matrix is one row and two columns
            equation=true;
        
            for number=1:V
                 isreal(Resistors) && row==1 && column>=2==false
                    disp(' Re-enter the resistances by which the number of resistors is even ')
            break;
                    
                if Resistors(number)>0 % value of the resistor is positive or otherwise
                    equation=true;
                elseif Resistors(number)<=0
                   
                    equation=false;
                    disp('  Re-enter the resistances where  its values are positive and real ')
                    break;
                    
                end
            end
        end
    end
    
    
    
end
disp ('===================================================================')

[darova]

I suggest you to re-write code as following

% if something1
%     % code
%     if something2
%         %code
%         %code
%         if something3
%             %code
%         end
%     end
% end
if something1
    % code1
end
if something2
    % code2
end
if something3
    % code3
end

Can you do this?

[Mariam Al Zarouni]

Hello againn, sorry but i've been working on what i have and got this.. for some reason, the sentence "Re-enter the resistances by which the number of resistors is even" keeps repeating with me in the output.. do you know a solution?

This is my code

clear all ;
close all;
equation=false;
while equation==false
    Resistors=input(' Enter values of two resistances in ohm [R1 R2]= '); % to enter tha values of the resistors
    V=length(Resistors);
  
    if mod(V,2) == 0
        [row,column]=size(Resistors);% matrix of the resistors
        if isreal(Resistors) && row==1 && column>=2 % this is to make sure the values are real and the matrix is one row and two columns
           
           for number=1:V
      
                if Resistors(number)>0 % value of the resistor is positive or otherwise
                    equation=true;
                else 
                    equation=false;
                   
                  break;
                end
           end
        end
      
        if equation==false
           disp('Re-enter the resistances where  its values are positive and real ')
           
        
        end
    end

  
    if equation==false
        disp('  Re-enter the resistances by which the number of resistors is even')
        
    end
end
disp ('===================================================================')

and this is my output

Enter values of two resistances in ohm [R1 R2]= [8 7 6]
  Re-enter the resistances by which the number of resistors is even
 Enter values of two resistances in ohm [R1 R2]= [8 -7]
Re-enter the resistances where  its values are positive and real 
  Re-enter the resistances by which the number of resistors is even
 Enter values of two resistances in ohm [R1 R2]= [7 8]
===================================================================

[darova]

• do you know a solution?

Solution for what? You don't want to see these?

[Mariam Al Zarouni]

i don't want to see line five from the output.. the second repeated sentence

[darova]

try to remov this line

[layla Hweij]

Hello All,

Im struggling with the same question but fruther this point, the continuation of the question says that we have to figure out the approximate current of the impedance matrix I have tried everything and its still not working.. so Mariam Al Zarouni, have you got the answer to that part or not ? please if you can send me the solution of the approximated current loop and how did you got it , would be fantastic

[layla Hweij]

and how did you use the phase and frquency in the Voltage eqaution.

[layla Hweij]

this is my code %%%%%% this the inversed impedance matrix multiplied by voltage vector to get the actual current, inwhich its outputs about are correct

Itrue= inv(z)*V;

%To get length of currents = 4

nn = numel(Itrue);

disp('The current:');

itrue = complex(Itrue);

disp(itrue);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

here is supposed code for the approximated current using the relaxation method but its not working it gives me zeros

disp('========= this is Successive Relaxation Method ========');

%to create the X matrix

b = size(z,1);

X = zeros(1,nn);

err=100;

xhistory=[];

while( err > tolerance)

for v = 1:b

Xprev = X(v);

X(v) = sum(Z(v,1:(v-1)).* X(1:(v-1)))+ sum(Z(v,(v+1):b).*X(v+1:b));

disp(X(v));

end

err = max(abs( X - Xprev));

disp(err);

xhistory =[xhistory,X];

break;

end

[layla Hweij]

this is rest of mariam question if you want a clearer verison of what im saying

==============================================================================

The Alpha should be positive real number between (0 and 2), check the value and enter it again

Enter the Alpha (between 0 and 2) to be used with the Successive Relaxation Method=0.5

==============================================================================

The impedance matrix to solve the mesh current is:

1.0e+02 *

0.1000 - 0.0100i -0.1000 + 0.0000i 0.0000 + 0.0000i 0.0000 + 0.0000i

-0.1000 + 0.0000i 0.3000 - 0.0003i -0.2000 + 0.0000i 0.0000 + 0.0000i

0.0000 + 0.0000i -0.2000 + 0.0000i 0.6000 - 0.0050i -0.4000 + 0.0000i

0.0000 + 0.0000i 0.0000 + 0.0000i -0.4000 + 0.0000i 1.4000 - 0.0005i

The voltage vector to solve the mesh current is:

10

0

0

0

I'm stuck at this point

||

v

approximated, exact=

1.7813+0.33424i 1.7857+0.33861i

0.816+0.15698i 0.81954+0.16005i

0.33475+0.067759i 0.33674+0.069396i

0.095532+0.019329i 0.096204+0.019862i

relative error, significant digit=

0.0034088 3

0.0056082 2

0.0074962 2

0.0087305 2

Magnitude Phase

1.8124 10.6275

0.8310 10.8894

0.3415 11.4432

0.0975 11.4380

Please if you can help us, it will be wonderful since I dont have much time left to the deadline ...

[darova]

Create new question

and use special button

[layla Hweij]

and here is the result including the voltage vector , the actual current and supposed relaxation method that will give me the approximated current

========================================

The Voltage vector to solve the mesh current is:

10

0

0

0

The current:

1.166 - 0.16397i

0.14959 - 0.28057i

0.062247 - 0.11448i

0.01285 - 0.034543i

========= this is Relaxation Method ========

0

0

0

0

0