Error catch when matIB2d goes unstable with new spreading operator

[nickabattista]

An error check ('try statement') should be incorporated when trying to form the spread operator but the code has already gone unstable due to large force deformations.

An error message such as the following is produced when such an event occurs:

Index exceeds array bounds.
Error in give_Spreading_Operator (line 105)
rX=abs(indsX(nn)-xAux);

Error in please_Find_Lagrangian_Forces_On_Eulerian_grid_VALENTINE (line 396)
S = give_Spreading_Operator(xLag,yLag,dx,dy,Nb,Nx,Ny);

[bvanstratum]

Thanks for making this great IB code available! I think I am getting the same error as @nickabattista. Do you know a workaround for this error message? I am attempting to run /Examples/Examples_First_Year_Seminar/Jellyfish_Material_512x512/main2d.m in MATLAB 2022a and 2024b. I believe I am getting the same error message as you posted here.

ndex exceeds the number of array elements. Index must not exceed 1.

Error in give_Spreading_Operator (line 97)
            rX=abs(indsX(nn)-xAux);

Error in please_Find_Lagrangian_Forces_On_Eulerian_grid (line 396)
S = give_Spreading_Operator(xLag,yLag,dx,dy,Nb,Nx,Ny);

Error in IBM_Driver (line 865)
    [SpreadOperator, Fxh, Fyh, F_Mass_Bnd, F_Lag, F_Poro, aggregate_list] = please_Find_Lagrangian_Forces_On_Eulerian_grid(dt, current_time, xLag_h, yLag_h, xLag_P, yLag_P, x, y, grid_Info, Lag_Struct_Params, springs_info, target_info, beams_info, nonInv_beams_info ,muscles_info, muscles3_info, mass_info, electro_potential, d_springs_info, gen_force_info, poroelastic_info, coagulation_info, aggregate_list, flag_Geo_Connect, geo_Connect_MAT);

Error in main2d (line 67)
[X, Y, U, V, xLags, yLags] = IBM_Driver(Fluid_Params,Grid_Params,Time_Params,Lag_Struct_Params,Output_Params,Lag_Name_Params,Con_Params);

/Examples/Examples_First_Year_Seminar/Jellyfish_Oscillator Gives a different error.

Error using please_Move_Lagrangian_Point_Positions
BLOW UP! (*forces TOO large*) -> try decreasing the time-step or decreasing material property stiffnesses

Which is helpful because if I reduce the timestep the code runs.

Is that the same remedy for the give_Spreading_Operator error as well?