printing values into a table

Hello Folks,

I am trying to create a code that I will solve a system of nonlinear equations and print the solutions into a table in a .doc file. The equations are functions of Theta. I want to print the solution to the system of equations for theta = 0:30:360.

I created the following code:

function F = Solution(x)
Lab = .1;
Lbc = .6;
Lcd = .3;
Lad = .4;
fid = fopen('Solution.doc','w');
fprintf(fid,'theta   x1       x2       x3    x4   \n');
fprintf(fid,'_______________________________________________________\n')
n=0; 
for theta=0:30:360
  n=n+1;
rabx = Lab*cosd(theta)
raby = Lab*sind(theta)  
F = [ 
  (x(1))^2 + (x(2)^2)- Lbc^2;   
 (x(3))^2 + (x(4))^2 - Lcd^2;
  raby + x(2) + x(4);
  rabx + x(1) + x(3) - Lad];
tab=[theta;x(1);x(2);x(3);x(4)];
fprintf(fid,'%5d %9.f %8.3f %8.3f %12.4f %12.4f\n', tab);
end
end

When I try to run the code, using fsolve, I get the following error : Too many open files. Close files to prevent MATLAB instability.

Caused by: Unknown exception

How can I fix this?

Thanks in advance.

Answer 1

[Walter Roberson]

You have

fid = fopen('Solution.doc','w');

but no-where in your code do you have

fclose(fid)

so you are leaving the file open :(

[Fabiano Da Mota]

Hello Walter, Thank you for your response. fclose(fid) got rid of the error. Now, the Matlab is not solving the functions for each value of theta. It is only solving for one value but printing it 13 times. Please see the attached picture.

I also update the code to the following:

function F = Solution(x)
Lab = .1;
Lbc = .6;
Lcd = .3;
Lad = .4;
fid = fopen('Solution.doc','w');
fprintf(fid,'theta         x1            x2          x3         x4   \n');
fprintf(fid,'_______________________________________________________\n')
n=0;
for theta=0:30:360
  n=n+1;
    theta
rabx = Lab*cosd(theta);
raby = Lab*sind(theta);
F = [ 
  (x(1))^2 + (x(2)^2)- Lbc^2;   
 (x(3))^2 + (x(4))^2 - Lcd^2;
  raby + x(2) + x(4);
  rabx + x(1) + x(3) - Lad];
tab=[theta;x(1);x(2);x(3);x(4)];
fprintf(fid,'%9.3f %9.3f %8.3f %8.3f %12.4f \n', tab);
end
fclose(fid)
end

Do you have an idea of how I could fix this?

Thank you once again.

[Walter Roberson]

The code is doing what you asked it to do, which is to print out each theta value together with the unmodified x(1), x(2), x(3), x(4) values.

Perhaps you wanted to print out the F values instead of the x values?