How do i add all the values which i get using eval function?

prompt = {'Enter the forces(kN): '};
title = 'Environmental forces';
answer = inputdlg(prompt,title);
f = str2num(answer{:});
for ii=1:numel(f)
    eval(sprintf('f%d = %f\n',ii,f(ii)))
end
prompt1 = {'Enter the respective angles: '};
title1 = 'Angle w.r.t x-axis';
answer1 = inputdlg(prompt1, title1);
a = str2num(answer1{:});
for jj=1:numel(a)
    eval(sprintf('a%d = %f\n',jj,a(jj)))
end

for jj=1:numel(a)
    string='f(jj)*cos(jj)';
    eval(string)
end
in this code i am getting several values for string. I have to add all those values. can anyone help?

Answer 1

[Jos (10584)]

Avoid EVAL !!!

You do not want to store a series of related values in separate variables f1 = .. f2 = .. but rather in a single variable with multiple elements f(1) = .. f(2) = ..

Your codes is almost there. Just remove the evals ...

prompt = {'Enter the forces(kN): '};
title = 'Environmental forces';
answer = inputdlg(prompt,title);
f = str2num(answer{:});
prompt1 = {'Enter the respective angles: '};
title1 = 'Angle w.r.t x-axis';
answer1 = inputdlg(prompt1, title1);
a = str2num(answer1{:});

if numel(f) ~= numel(a)
   error('The vectors should have the same number of elements') ;
else
   sum=0 ;
   for jj=1:numel(a)
      sum = sum + f(jj)*cos(a(jj)) ;
   end
   % or use the power of matlab:
   % sum = sum(f.*cos(a)) 
end

Lesson to be learned: avoid eval!

[DIJESH]

thank you for the help!!! :)

Answer 2

[rifat]

prompt = {'Enter the forces(kN): '};
title = 'Environmental forces';
answer = inputdlg(prompt,title);
f = str2num(answer{:});
for ii=1:numel(f)
    eval(sprintf('f%d = %f\n',ii,f(ii)))
end
prompt1 = {'Enter the respective angles: '};
title1 = 'Angle w.r.t x-axis';
answer1 = inputdlg(prompt1, title1);
a = str2num(answer1{:});
for jj=1:numel(a)
    eval(sprintf('a%d = %f\n',jj,a(jj)))
end

sum=0;
for jj=1:numel(a)
    string='f(jj)*cos(jj)';
    sum=sum+eval(string);
end

[DIJESH]

thanx for trying rifat :)