function result = Mie_abs(m, x)



% Computation of the Absorption Efficiency Qabs

% of a sphere of size parameter x, 

% complex refractive index m=m'+im", 

% based on nj internal radial electric field values

% to be computed with Mie_Esquare(nj,m,x)

% Ref. Bohren and Huffman (1983) BEWI:TDD122,

% and my own notes on this topic;

% k0=2*pi./wavelength;

% x=k0.*radius;

% C. M鋞zler, May 2002, revised July 2002.



nj=100*round(2+x+4*x.^(1/3))+300;

e2=imag(m.*m);

dx=x/nj;

x2=x.*x;

nj1=nj+1;

xj=(0:dx:x);

en=Mie_Esquare(m,x,nj);

en1=0.5*en(nj1).*x2;     % End-Term correction in integral

enx=en*(xj.*xj)'-en1;    % Trapezoidal radial integration

inte=dx.*enx;

Qabs=4.*e2.*inte./x2;

result=Qabs;