Can't excute graphical function in Excel Add-in component

I have this function to build with Matlab Compiler to use in Excel:

function y=borne_prob(eta,beta)

x1=[1 2 3 4 5 6 7 8 9]'; M=wblstat(eta,beta); lambda_ref=1/M;

x2=[0 1/3*lambda_ref 2/3*lambda_ref lambda_ref 4/3*lambda_ref 5/3*lambda_ref 6/3*lambda_ref ... 7/3*lambda_ref 8/3*lambda_ref]';

x3=(x2./(beta./eta.^beta)).^(1/(beta-1));

v= x2(1:8)+(x2(2:9)-x2(1:8))/2; x4=[0;v]; x5=(x4./(beta./eta.^beta)).^(1/(beta-1)); y=[x1 x3 x2 x5 x4];

x=0:.1:(max(x5)+5); figure() plot(x,wblpdf(x,eta,beta)./wblcdf(x,eta,beta,'upper'),'linewidth',2); hold on; for i=1:9 plot([x5(i) x5(i)],[0 x2(3)],'k','linewidth',3); hold on; end xlabel('âge (années)'); ylabel('Taux de défaillance'); grid on; grid minor; end

The graphical output of this function doesn't work in Excel (from Excel Add-in component), but works when executed from matlab. How can I fix this ?