Errors with s-function level 1 in simulink

[HFAI]

Hi all,

I am modeling a separator model with pressure and water level as 2 variables.
I first made an m-file(hamda.m) with ode23tb, which is working( 4 plots: pressure, water level, flow of liq output and flow of gas output.
then I used an level 1 s-function( gabileh) applying the m-file(hamda.m) I created as fellow
function [sys,x0,str,ts,simStateCompliance] = gabileh(t,x,u,flag,varargin)

% M-File S-Function implementing

QLi = u(1); Qgi = u(2); kv1 = u(3); kv2 = u(4);


switch flag,

%%%%%%%%%%%%%%%%%%
% Initialization %
%%%%%%%%%%%%%%%%%%
case 0,
[sys,x0,str,ts, simStateCompliance] = mdlInitializeSizes(t,x,u,flag);

%%%%%%%%%%%%%%%
% Derivatives %
%%%%%%%%%%%%%%%

case 1,
sys = mdlDerivatives(t,x,u,QLi,Qgi,kv1,kv2);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Update, Output, and Terminate %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
case {2, 4, 9},
sys = []; % do nothing

%%%%%%%%%%
% Output %
%%%%%%%%%%
case 3
sys = mdlOutputs(t,x,u);

otherwise
DAStudio.error('Simulink:blocks:unhandledFlag', num2str(flag));
end


%
%===================================================================================
% mdlInitializeSizes
% Return the sizes, initial conditions, and sample times for the S-function.
%===================================================================================
%
function [sys, x0,str,ts] = mdlInitializeSizes

sizes = simsizes;
sizes.NumContStates = 2;
sizes.NumDiscStates = 0;
sizes.NumOutputs = 4;
sizes.NumInputs = 4;
sizes.DirFeedthrough = 0;
sizes.NumSampleTimes = 1;

sys = simsizes(sizes);

x0 = [];
str = [];
ts = [0 0]; % continuous sample time: [period, offset]

% Specify the block simStateCompliance. The allowed values are:
% 'UnknownSimState', < The default setting; warn and assume DefaultSimState

simStateCompliance = 'UnknownSimState';

% end mdlInitializeSizes

%
%===================================================================================
% mdlDerivatives
%
%===================================================================================
%
function sys = mdlDerivatives(t,x,u,varargin)

QLi = u(1); Qgi = u(2); kv1 = u(3); kv2 = u(4);

sys = hamda(t,x,u);

% end mdlInitializeSizes

%=============================================================================
% mdlOutputs
% Return the output vector for the S-function
%=============================================================================
%
function sys = mdlOutputs(t,x,u)
sys =Qgt;
sys =QLt;
sys = x;


% end mdlOutputs


when I used the level-1 s-function in a simulink with 4 inputs and 4 ouputs,
I keep having the same error:

Error in 'seprig/M-file S-Function1' while executing M-File S-function 'gabileh', flag = 0 (initialize), at start of simulation. MATLAB error message:
Attempted to access u(1); index out of bounds because numel(u)=0.

please help, thanks in adavance

 

[NateD]

. </code><code>Error in 'seprig/M-file S-Function1' while executing M-File S-function 'gabileh', flag = 0 (initialize), at start of simulation. MATLAB error message:Attempted to access u(1); index out of bounds because numel(u)=0.This happens because you are trying to access the first element of the input vector 'u', which is not defined yet. You should define it in your initialization step (flag 0):switch flag, %%%%%%%%%%%%%%%%%% % Initialization % %%%%%%%%%%%%%%%%%% case 0, [sys,x0,str,ts, simStateCompliance] = mdlInitializeSizes(t,x,u,flag); QLi = u(1); Qgi = u(2); kv1 = u(3); kv2 = u(4); %%%%%%%%%%%%%%% % Derivatives % %%%%%%%%%%%%%%% case 1, sys = mdlDerivatives(t,x,u,QLi,Qgi,kv1,kv2); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Update, Output, and Terminate % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% case {2, 4, 9}, sys = []; % do nothing %%%%%%%%%% % Output % %%%%%%%%%% case 3 sys = mdlOutputs(t,x,u); otherwise DAStudio.error('Simulink:blocks:unhandledFlag', num2str(flag));endHope this helps.</code>