Extract positive value from solve function

eqs = [(A-a1)  == d, (A-a2)  == d2;
 S = solve(eqs, [A B]);
 a = S.A
 b = S.B

In the code above, all other variables are given so i AM solving for A and B. The code above alrEADY works and displays a solution but how will I extract the positive values of the solution only , and assign them to variables a and b?

Answer 1

[Torsten]

If a and b contain no more symbolic constants, then you can use

a = double(a);
b = double(b);
a = a(abs(imag(a)) < 1e-6);
b = b(abs(imag(b)) < 1e-6);
a = real(a);
b = real(b);

A = [];
B = [];
iter = 0;
for i = 1:numel(a)
  if a(i) >= 0 && b(i) >= 0
    iter = iter + 1;
    A(iter) = a(i);
    B(iter) = b(i);
  end
end
A
B

[Sashi Mendoza]

I tried inputting this, but hte code still yields 2 answers each for A and B

A =

0.8465 + 0.3307i

0.8465 - 0.3307i

B =

0.4579 - 0.2660i

0.4579 + 0.2660i

[Torsten]

Since you get complex solutions to your system, the two circles don't cross for the midpoints and radii given.

In order that they have points in common, the condition

d + d2 >= sqrt((a1-a2)^2 + (c1-c2)^2)

must be met.

I modified the code from above.