Hello i have a problem with my S function the erroe is :'Error using PMSMMainprog (line 52) State derivatives returned by S-function 'PMSMach' in 'PMSMpanel/Induction machine/S-Function' during flag=1 call must be a real vector of length 4' this is m

Hello i have a problem with my S function the erroe is :'Error using PMSMMainprog (line 52) State derivatives returned by S-function 'PMSMach' in 'PMSMpanel/Induction machine/S-Function' during flag=1 call must be a real vector of length 4' this is my code: function [sys,x0,str,ts] =PMSMach(t,x,u,flag,Rs,Lsd,Lsq,fluxm,np,J,B,xi) %CSFUNC An example M-file S-function for defining a continuous system. % Example M-file S-function implementing continuous equations: % x' = Ax + Bu % y = Cx + Du % See sfuntmpl.m for a general S-function template. switch flag,

%%%%%%%%%%%%%%%%%%
% Initialization %
%%%%%%%%%%%%%%%%%%
case 0,
  [sys,x0,str,ts]=mdlInitializeSizes(t,x,u,flag,Rs,Lsd,Lsq,fluxm,np,J,B,xi);

%%%%%%%%%%%%%%%
% Derivatives %
%%%%%%%%%%%%%%%
case 1,
  sys=mdlDerivatives(t,x,u,flag,Rs,Lsd,Lsq,fluxm,np,J,B,xi);

%%%%%%%%%%%
% Outputs %
%%%%%%%%%%%
case 3,
  sys=mdlOutputs(t,x,u,flag,Rs,Lsd,Lsq,fluxm,np,J,B,xi);

%%%%%%%%%%%%%%%%%%%
% Unhandled flags %
%%%%%%%%%%%%%%%%%%%
case { 2, 4, 9 },
  sys = [];

%%%%%%%%%%%%%%%%%%%%
% Unexpected flags %
%%%%%%%%%%%%%%%%%%%%
otherwise
  error(['Unhandled flag = ',num2str(flag)]);
end
% end csfunc
%
%=============================================================================
% mdlInitializeSizes
% Return the sizes, initial conditions, and sample times for the S-function.
%=============================================================================
%
function [sys,x0,str,ts]=mdlInitializeSizes(t,x,u,flag,Rs,Lsd,Lsq,fluxm,np,J,B,xi)

sizes = simsizes; sizes.NumContStates = 4; sizes.NumDiscStates = 0; sizes.NumOutputs = 6; sizes.NumInputs = 3; sizes.DirFeedthrough = 0; sizes.NumSampleTimes = 1;

sys = simsizes(sizes); x0 = xi; str = []; ts = [0 0]; % end mdlInitializeSizes % %============================================================================= % mdlDerivatives % Return the derivatives for the continuous states. %============================================================================= % function sys=mdlDerivatives(t,x,u,flag,Rs,Lsd,Lsq,fluxm,np,J,B,xi)

%state variables: isd=x(1); isq=x(2); wr=x(3); theta=x(4);

% input signals: usd=u(1); usq=u(2); TL_extra=u(3);

Tem=((3*np*fluxm*isq)/2); Ter=((3*np*(Lsd-Lsq)*isd*isq)/2); Te=(3/2)*np*((fluxm*isq)+(Lsd-Lsq)*isd*isq); TL=B*(wr/np)+TL_extra;

sys(1)=((usd+(wr*Lsq*isq)-(Rs*isd))/Lsd); sys(2)=((usq-(wr*fluxm)-(wr*Lsd*isd)-(Rs*isq))/Lsq); sys(3)=((np/J)*(Te-TL)); sys(4)=wr;

% end mdlDerivatives % %============================================================================= % mdlOutputs % Return the block outputs. %============================================================================= % function sys=mdlOutputs(t,x,u,flag,Rs,Lsd,Lsq,fluxm,np,J,B,xi)

isd=x(1); isq=x(2); wr=x(3); theta=x(4);

Tem=((3*np*fluxm*isq)/2); Ter=((3*np*(Lsd-Lsq)*isd*isq)/2); Te=Tem+Ter;

sys = [isd,isq,Tem,Ter,wr/np,theta/np]; % end mdlOutputs i do not know what the problem is can you please help me