Solve function with variables

syms c ho
S=solve('c^2/(2*R)+(2*delta_p*c*(pi-2))/(pi*Er)+ho-h_lk=0','w(i)=ho+(2*c*delta_p)/Er');

I am trying to solve variables in the equation, only c and ho are the unknown variables. w(i) is changing in the loop, and I want to calculate variable values continuously. Other varibles are the known and assigned values. How can I solve the problem? solve function currently wants everything numerical except the unknowns.

Thanks

Emrecan

[Azzi Abdelmalek]

what are the unknown variables?

[Emrecan]

c and ho are the unknown variables

Answer 1

[Matt Fig]

You can specify the variables of interest to the solve command.

S=solve('c^2/(2*R)+(2*delta_p*c*(pi-2))/(pi*Er)+ho-h_lk=0','w(i)=ho+(2*c*delta_p)/Er','c','ho');

To replace the indexed w, use:

 S=solve('c^2/(2*R)+(2*delta_p*c*(pi-2))/(pi*Er)+ho-h_lk=0',sprintf('%f=ho+(2*c*delta_p)/Er',w(ii)),'c','ho');

Answer 2

[Azzi Abdelmalek]

 s1='c^2/(2*R)+(2*delta_p*c*(pi-2))/(pi*Er)+ho-h_lk=0',
 s2=[num2str(w(i)) '=ho+(2*c*delta_p)/Er']);
 s=solve(s1,s2,'c','ho')

[Emrecan]

I need something like num2str, but in this case it does not work.

[Matt Fig]

What does that mean, "It doesn't work"? Did you get an error? If so, what error? Did MATLAB crash? Did the computer catch fire? Please be more specific. Also, you might try SPRINTF as I show above.

Answer 3

[Walter Roberson]

syms c ho
S = solve(c^2/(2*R)+(2*delta_p*c*(pi-2))/(pi*Er)+ho-h_lk, ho+(2*c*delta_p)/Er - w(i), c, ho);