MATLAB: Fsolve or fzero for this system of nonlinear equation

equationfsolvefzeroMATLABnonlinearOptimization Toolbox

my problem is :
I need solve this function F = di – x(1)*expint(ti*x(2)) … or 0 = di – x(1)*expint(ti*x(2))
where,
x(1) and x(2) are constants ..FOR TO FIND
di , ti are 1xN matriz of measure data… data length subject to change I have the following sample data. ————– for example :
ti = 1.0e+03 *[ 9.0000 3.6000 1.8000 1.2857 0.9000] di = [0.0400 0.0800 0.1300 0.1800 0.2300]
PLEASE, HELP/ I've tried with FZERO and FSOLVE but without success

Best Answer

ti = 1.0e+03 *[ 9.0000 3.6000 1.8000 1.2857 0.9000] ; di = [0.0400 0.0800 0.1300 0.1800 0.2300]; x=ti; y=di; a0=[1,1e-3]; format long g a=lsqcurvefit(@(a,x)a(1)*expint(a(2)*x),a0,x,y) x1=a(1) x2=a(2)
plot(x,y,'*',x,a(1)*expint(a(2)*x),'-')