Problems evaluating Q-function. Error : The argument of the Q function must be a real array.

I have a problem when I evaluate the results of qfunc(x). The reason behind this is that my input x to the qfunc, is actually a string, that contains a L symbol whose value is not known at the moment, so it does not evaluate it.

Programs runs well upto assignment of I and temp. when it enters in j for loop and start calculating P_d(j), it will create an error as

*??? Error using ==> qfunc at 19

The argument of the Q function must be a real array.

Error in ==> abc at 28

    P_d(j)=simplify(qfunc(((E_l(j)/(p.^2))-s(j)-1)*(sqrt(M/(2*s(j)+1)))))
 *

*Here is the code *

N=16

s=[.38 1.37 .32 .24 .35 .27 .39 .38 .74 .37 .51 .26 .31 .25 .23 .81]

r=[857 206 853 900 611 808 561 325 212 391 219 830 308 650 924 138]

p=1

c=[8.94 1.68 3.81 6.91 9.01 2.07 3.43 3.44 1.79 3.38 1.63 1.66 1.02 3.3 1.98 8.91]

a=.1

b=.2

M=150

g=1

syms L

for k=1:N

    temp(k)=(p.^2)*(0.5+sqrt(((2*s(k)+1)/s(k))*((-1/M)*log10((L)*c(k)/(r(k)*sqrt(2*s(k)+1)))+s(k)/4)))

    E_l(k)=simplify (temp(k))

end

I=[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]

temp=[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]

for j=1:N

    P_d(j)=simplify(qfunc(((E_l(j)/(p.^2))-s(j)-1)*(sqrt(M/(2*s(j)+1)))))

    P_m(j)=1-P_d(j)

    temp(j)=c(j)*P_m(j)

    I(j)=I(j)+temp(j)

end

[Suwas Karki]

Nobody has answer for this problem ???

[xiaomin QI]

do you have some ideas about this problem?