how to create a txt file of output for a program in Matlab s

how to create a .txt file of output for a program in Matlab     \"sprintf\"??????????????????

The out I am getting from my function for finding the roots of a quadratic formula needs to be saved and printed in a .txt file..............

Copy of my formula

function [ root1,root2 ] = quadratic_formula( a,b,c )

% Design a Matlab using the algorithm for solving quadratic equations

% Prompt the user to enter the coefficients

% ax^2+bx+c = 0

a(1) = input(\'Please enter a value for (a) >> \');

b(1) = input(\'Please enter a value for (b) >> \');

c(1) = input(\'Please enter a value for (c) >> \');

if a == 0

disp(\'Error: Value Will Result In An Undefined Answer\')

disp(\'PLEASE ENTER A VALUE > 0\')

end

if b^2-4*a*c > 0

root1 = (-b+sqrt(b^2-4*a*c))/2*a; % Root of the equation

root2 = (-b-sqrt(b^2-4*a*c))/2*a;

elseif b^2-4*a*c == 0;

root1 = -b/2*a;

disp(\'There is only one root\')

else

disp(\' Error: Imaginary Roots\')

disp(\'No Real Solution\')

end

end

Solution

fprintf is used to save a data to .txt file in MATLAB.

first you need to open a file in write mode with a file handler like

myfile = fopen(\'File.txt\', \'w\');

where w indicates file with file handler myfile and filename File.txt is in write mode.

now when you want to save the data to File.txt use fprintf as below:

it will save the value of B in File.txt

and than close the file using file handle as below:

fclose(myfile);

now for your MATLAB program find the updated program as below:

function [ root1,root2 ] = quadratic_formula( a,b,c )
% Design a Matlab using the algorithm for solving quadratic equations
% Prompt the user to enter the coefficients
% ax^2+bx+c = 0

% open File.txt with handle myfile in write mode

myfile = fopen(\'File.txt\', \'w\');

a(1) = input(\'Please enter a value for (a) >> \');
b(1) = input(\'Please enter a value for (b) >> \');
c(1) = input(\'Please enter a value for (c) >> \');

if a == 0
disp(\'Error: Value Will Result In An Undefined Answer\')
disp(\'PLEASE ENTER A VALUE > 0\')
end

if b^2-4*a*c > 0

root1 = (-b+sqrt(b^2-4*a*c))/2*a; % Root of the equation
root2 = (-b-sqrt(b^2-4*a*c))/2*a;

%save values of root1 and root2 in File.txt

fprintf(myfile,\'%0.4f\ \',root1);
fprintf(myfile,\'%.4f\ \',root2);

elseif b^2-4*a*c == 0;
root1 = -b/2*a;

%save values of root1 in File.txt
fprintf(myfile,\'%.4f\ \',root1);

disp(\'There is only one root\')

else

disp(\' Error: Imaginary Roots\')
disp(\'No Real Solution\')

end

end

fclose(myfile);

or you can also do like this in which every display statement is also in File.txt

function [ root1,root2 ] = quadratic_formula( a,b,c )
% Design a Matlab using the algorithm for solving quadratic equations
% Prompt the user to enter the coefficients
% ax^2+bx+c = 0

% open File.txt with handle myfile in write mode

myfile = fopen(\'File.txt\', \'w\');

pqr1 = \'Error: Value Will Result In An Undefined Answer\';
pqr2 = \'PLEASE ENTER A VALUE > 0\';
pqr3 = \'There is only one root\';
pqr4 = \' Error: Imaginary Roots\';
pqr5 = \'No Real Solution\';

a(1) = input(\'Please enter a value for (a) >> \');
b(1) = input(\'Please enter a value for (b) >> \');
c(1) = input(\'Please enter a value for (c) >> \');

if a == 0
%save display statement in File.txt
fprintf(myfile,\'%s\ \',pqr1);
fprintf(myfile,\'%s\ \',pqr2);
end

if b^2-4*a*c > 0

root1 = (-b+sqrt(b^2-4*a*c))/2*a; % Root of the equation
root2 = (-b-sqrt(b^2-4*a*c))/2*a;

%save values of root1 and root2 in File.txt

fprintf(myfile,\'%0.4f\ \',root1);
fprintf(myfile,\'%0.4f\ \',root2);

elseif b^2-4*a*c == 0;
root1 = -b/2*a;

%save values of root1 in File.txt
fprintf(myfile,\'%0.5fn\',root1);

%save display statement in File.txt

fprintf(myfile,\'%s\ \',pqr3);

else

%save display statement in File.txt

fprintf(myfile,\'%s\ \',pqr4);
fprintf(myfile,\'%s\ \',pqr5);

end

end

fclose(myfile);

note %.4f will display result upto 4 decimal places.