usage of syms in for loop?

for i=1:15

      bx=zeros(15,1)

      dx=zeros(15,1)

syms  b d

VNX(i) = ((Av(i)*Fy(i)*0.8*d)/S(i))+(0.16*sqrt(Fck(i))*b*d)+((0.48*P(i))/sqrt(Fck(i)))

assume(b>0)

assume(d>0)

sol = solve([VNX], [b,d]);

bx(i) = sol.b

dx(i) = sol.d

end

Answer 1

[Walter Roberson]

You did not ask a question. But meanwhile you need to fix the problems I described for your other question http://uk.mathworks.com/matlabcentral/answers/265042-how-to-optimize-this-solution#answer_207291

By the way, you do not want

      bx=zeros(15,1)
      dx=zeros(15,1)

inside your "for" loop, as that is going to reinitialize all of bx and dx each iteration of "i", overwriting all the answers you got before.

[abdul haakim mohammed]

i want to use the for loop for syms but i am not ale to do so it is giving me an error that says

"The following error occurred converting from sym to double: Error using symengine (line 58) DOUBLE cannot convert the input expression into a double array. If the input expression contains a symbolic variable, use VPA."

[Walter Roberson]

Before the loop, use

      bx = sym(zeros(15,1));
      dx = sym(zeros(15,1));