About "Warning: Ignoring fz<0 entries at start of vector " may be a bug

[wj2392907320]

"Ignoring fz<0 entries at start of vector" is warned when I run modified example_sphere.m file, but when I open the find_equilibrium.m file to find the corresponding 39 lines, run find(fz<0,1) is not equal to 1, but to 3, so the program should not run warning('Ignoring fz<0 entries at start of vector'), but the result is to continue executing the program below "if zeroindex ==1". The results are shown in the following charts.
I changed 4 things, 1 is n_medium=1.53 and n_particle=1.33; 2 is NA=0.8; 3 is radius=10e-6; 4 is linspace(-4,4,80)->linspace(-30,30,300).




Thank you Dr. Lenton for your patient answer earlier. I am currently writing a simulation paper on vortex optical tweezers, and I need to use your optical tweezers kit for simulation, but I still don't know enough about some parts of the program. Thank you for your help, and I can include you as the author when the paper is published. What do you think?