Simulataneous equation solver code

Hi, I am trying to come up with a simultaneous equation solver that will ask a user for the number of simultanous equations to be solved and the number of coefficients in the simultaneous equations after which a for loop will be used to enter the number of coeffiecients for the number of equations.

Attached is the matlab code

% function for coefficient entry
function s = myfunc_Q2a(x)
s=zeros;
for i=1:x
s(i)=str2double(inputdlg('Enter coefficients: '));
end 
end 

% script that calls on the above function
g=msgbox('Equation is in the form: x1*a1 + x2*a2 + an*xn= b ');
waitfor(g)
n=str2double(inputdlg('Enter the number of simultaneous equations to be solved: '));
x=str2double(inputdlg('Enter the number of coefficients in the equation: '));
A=zeros;
B=zeros;
s=zeros;
for j=1:n
  z(j)=myfunc_Q2a(x);  
end
 

I am receiving an error that states left and right hand side have different number of elements, however when I choose

n=2 and x=1 I dont receive an error.

[Ghazwan]

is it maybe x=1 is the only integer you are entering?

You have a counter i=1:x. x has to be an integer.

Answer 1

[Gowthami]

Hi Tadiwa,

Here at

z(j)=myfunc_Q2a(x);  

You are assigning the 'x'(number of coefficients) length elements array to 'z(j)' which is 1 element of a vector. Because of this you are encountering the error 'Unable to perform assignment because the left and right sides have a different number of elements.'

For example, if n = 2 and x = 3, The left side of this line of code refers to 1 element of z. The right side refers to a 3-element array.

As you mentioned you didn't receive any error when n = 2 and x = 1, because the left side of this line of code refers to 1 element of z and the right side refers to only 1 element. So, you are not encountering any error messages.

For resolve this issue, you may use a 2-D matrix. Please find the following code snippet for the same,

z=zeros(n,x);
for j=1:n
    z(j,:)=myfunc_Q2a(x);
end

You may create a 2-D matrix where each row contains one of these 'x' length arrays or you could create a cell array.

I hope it helps.

[Tadiwa]

This worked perfectly, many thanks