How can i solve the error in the code given below? I'm getting the following error In an assignment A(:) = B, the number of elements in A and B must be the same.

syms T

h=1.054*(10^-34);

T=[1:20:1001];

kb=1.38*(10^-23);

g=1.1;

vd=6703.3;

M=4.6637*(10^-26);

td=355.33;

A=(h*(g^2)*(kb^2))/(M*(vd^2)*td*(h^2));

c=((kb^4).*(T.^3))/(2*(pi^2)*vd*(h^3));

g1=2*(10^-4);

V=2.0024*(10^-29);

syms x xd

syms ru(x) ru1(x) ru2(x) f(x) f1(x) q kc

ru(x)=(1./(A.*exp(-td./(3.*T)).*(T.^3)*(x^2)));

ru1(x)=(4*pi*(vd^3)*(h^4))./(g1*V*(kb^4)*(T.^4)*(x^4));

ru2=ru+ru1;

f(x)=((x^2)*exp(x))/((exp(x)-1)^2);

f1=ru2*f;

k=matlabFunction(f1);

xd=td./T ;

q=0;

kc=0;

for i=1:1:length(xd)

    q(i)=integral(k,0,xd(i),'ArrayValued',true);

kc(i)=c(i).*q(i)

end

I'm getting the following error

In an assignment A(:) = B, the number of elements in A and B must be the same.

Error in hw4 (line 26)

    q(i)=integral(k,0,xd(i),'ArrayValued',true);

[Karan Gill]

Format your code.

[Aqeel Mohammed Abdul Mageeth]

I have made it more readable. Please help

Answer 1

[Robert]

Your function k returns 51 outputs. MATLAB issues that error when your code asks to store the 51 corresponding integrals in the one spot you have named: q(i). Instead, you could pre-allocate an array for q and kc and fill the rows with each iteration of the for loop.

q = nan(length(k(0)), length(xd)); 
kc = q; 

for i=1:length(xd) % if step ~= 1, you will need to change size of q and kc
  I = integral(k,0,xd(i),'ArrayValued',true);
  q(i, :) = I;
  kc(i, :) = c(i) .* I;
end