"the function return value 'self inductance' might be unset"

Question

rose wright 2018-3-19

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/389268-the-function-return-value-self-inductance-might-be-unset

评论： Star Strider 2018-3-20

hye, this is my codes,

function [ Selfinductance ] = Inductance(D_out,D_in,p)
u= pi*4*10.^-7;
y= 4*pi*p.^2;
X= (u*D_out.^3)/y;
a = D_in/ D_out;
B = (1 - a);
b = (1 + a);
m = X* (1-a.^2)*(1-a);
n = log(b/B) + (0.2235*(B/b))+ 0.726;
L = m*n
end
this codes is working perfectly but i got warning "the function return value 'self inductance' might be unset" and when i tried to call this function in another function, 
function [ qfactor] = qfactor(D_out,D_in,p) 
f= 0:8;
for i = 0:8
      L= Inductance(D_out,D_in,p);
      Q(i+1)= f(i+1)*L
end
end

I got this,

L =
     4.5579e-06
Error in Inductance (line 3)
u= pi*4*10.^-7;
Output argument "Selfinductance" (and maybe others) not assigned during call to "C:\Users\.......