Why simulation is taking too long to respond?

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roro6992
roro6992 on 14 Jun 2014
Commented: Geoff Hayes on 14 Jun 2014
Hello everyone..I am quite new to writing matlab s functions.Still i have written a matlab level-2 S function to model a physical system and eventually it has become large cause there are too many calculations. Ok..now while i am simulating the model including the s func block...the simulation is taking too long to respond and its just showing the word 'Initializing' in the bottom left corner and after sometime matlab stops responding. Why is this happening? Would u please check my code and tell whats wrong? The code is attached. Thank you!!
function moc_sfunc1(block)
setup(block);
%endfunction
function setup(block)
%%Register dialog parameter:
block.NumDialogPrms = 0;
%%Register number of input and output ports
block.NumInputPorts = 10;
block.NumOutputPorts = 2;
%%Setup functional port properties to dynamically inherited.
block.SetPreCompInpPortInfoToDynamic;
block.SetPreCompOutPortInfoToDynamic;
block.InputPort(1).Complexity = 'Real';
block.InputPort(1).DataTypeId = 0; %double
block.InputPort(1).SamplingMode = 'Sample';
block.InputPort(1).Dimensions = 1;
block.InputPort(2).Complexity = 'Real';
block.InputPort(2).DataTypeId = 0;
block.InputPort(2).SamplingMode = 'Sample';
block.InputPort(2).Dimensions = 1;
block.InputPort(3).Complexity = 'Real';
block.InputPort(3).DataTypeId = 0;
block.InputPort(3).Dimensions = 1;
block.InputPort(3).SamplingMode = 'Sample';
block.InputPort(4).Complexity = 'Real';
block.InputPort(4).DataTypeId = 0;
block.InputPort(4).Dimensions = 1;
block.InputPort(4).SamplingMode = 'Sample';
block.InputPort(5).Complexity = 'Real';
block.InputPort(5).DataTypeId = 0;
block.InputPort(5).Dimensions = 1;
block.InputPort(5).SamplingMode = 'Sample';
block.InputPort(6).Complexity = 'Real';
block.InputPort(6).DataTypeId = 0;
block.InputPort(6).Dimensions = 1;
block.InputPort(6).SamplingMode = 'Sample';
block.InputPort(7).Complexity = 'Real';
block.InputPort(7).DataTypeId = 0;
block.InputPort(7).Dimensions = 1;
block.InputPort(7).SamplingMode = 'Sample';
block.InputPort(8).Complexity = 'Real';
block.InputPort(8).DataTypeId = 0;
block.InputPort(8).Dimensions = 1;
block.InputPort(8).SamplingMode = 'Sample';
block.InputPort(9).Complexity = 'Real';
block.InputPort(9).DataTypeId = 0;
block.InputPort(9).Dimensions = 1;
block.InputPort(9).SamplingMode = 'Sample';
block.InputPort(10).Complexity = 'Real';
block.InputPort(10).DataTypeId = 0;
block.InputPort(10).Dimensions = 1;
block.InputPort(10).SamplingMode = 'Sample';
block.OutputPort(1).Complexity = 'Real';
block.OutputPort(1).DataTypeId = 0;
block.OutputPort(1).SamplingMode = 'Sample';
block.OutputPort(1).Dimensions = 1;
block.OutputPort(2).Complexity = 'Real';
block.OutputPort(2).DataTypeId = 0;
block.OutputPort(2).SamplingMode = 'Sample';
block.OutputPort(2).Dimensions = 1;
% Register the sample times.
block.SampleTimes = [-1 0];
% -----------------------------------------------------------------
% Options
% -----------------------------------------------------------------
% Specify if Accelerator should use TLC or call back to the
% MATLAB file
block.SetAccelRunOnTLC(false);
%%Set the block simStateCompliance to default (i.e., same as a built-in block)
block.SimStateCompliance = 'DefaultSimState';
%%Register methods %%
block.RegBlockMethod('PostPropagationSetup', @DoPostPropSetup);
block.RegBlockMethod('InitializeConditions', @InitializeConditions);
block.RegBlockMethod('Start', @Start);
block.RegBlockMethod('Outputs', @Outputs);
%endfunction
function DoPostPropSetup(block)
%%Setup Dwork
I = 21; %%no. of length steps
block.NumDworks = 7;
block.Dwork(1).Name = 'Q_A'; %Q_A(1),...Q_A(I)
block.Dwork(1).Dimensions = I;
block.Dwork(1).DatatypeID = 0;
block.Dwork(1).Complexity = 'Real';
block.Dwork(1).UsedAsDiscState = true;
block.Dwork(2).Name = 'P_A'; %%P_A(1),....P_A(I)
block.Dwork(2).Dimensions = I;
block.Dwork(2).DatatypeID = 0;
block.Dwork(2).Complexity = 'Real';
block.Dwork(2).UsedAsDiscState = true;
block.Dwork(3).Name = 'Q_B'; %Q_B(1),...Q_B(I-1)
block.Dwork(3).Dimensions = I-1;
block.Dwork(3).DatatypeID = 0;
block.Dwork(3).Complexity = 'Real';
block.Dwork(3).UsedAsDiscState = true;
block.Dwork(4).Name = 'P_B'; %P_B(1),....P_B(I-1)
block.Dwork(4).Dimensions = I-1;
block.Dwork(4).DatatypeID = 0;
block.Dwork(4).Complexity = 'Real';
block.Dwork(4).UsedAsDiscState = true;
block.Dwork(5).Name = 'k1';
block.Dwork(5).Dimensions = 1;
block.Dwork(5).DatatypeID = 0;
block.Dwork(5).Complexity = 'Real';
block.Dwork(5).UsedAsDiscState = true;
block.Dwork(6).Name = 'k2';
block.Dwork(6).Dimensions = 1;
block.Dwork(6).DatatypeID = 0;
block.Dwork(6).Complexity = 'Real';
block.Dwork(6).UsedAsDiscState = true;
block.Dwork(7).Name = 'k3';
block.Dwork(7).Dimensions = 1;
block.Dwork(7).DatatypeID = 0;
block.Dwork(7).Complexity = 'Real';
block.Dwork(4).UsedAsDiscState = true;
%%Register all tunable parameters as runtime parameters.
%endfunction
function Start(block)
%%Initialize Dwork
I=21;
block.Dwork(1).Data = zeros(1, I);
block.Dwork(2).Data = zeros(1, I);
block.Dwork(3).Data = zeros(1, I-1);
block.Dwork(4).Data = zeros(1, I-1);
%endfunction
function InitializeConditions(block)
g=9.81;
Qo=block.InputPort(8).Data;
f=block.InputPort(5).Data;
d=block.InputPort(3).Data;
D=block.InputPort(4).Data;
S=3.14*D^2/4;
L= block.InputPort(7).Data;
R=392;
T=block.InputPort(10).Data;
P0 =block.InputPort(9).Data;
H=block.InputPort(6).Data;
dx=5000;
theta=atan(H/L); % all the parameter values
Z0=.8;
CF=0;
while CF==0
c=sqrt(Z0*R*T); % a loop to find out the actual value of compressibility
if H~=0
sigma=(2*g*sin(theta))/c^2;
lamda=(2*Qo^2*f*c^4*d^2)/(D*S^2*g*sin(theta));
PL = sqrt((P0^2-lamda*(exp(sigma*L)-1))*exp(-sigma*L));
else phy=(f/D)*(2*c*d*Qo/S)^2;
PL=sqrt(P0^2-phy*L);
end
Pav= 0.5*(P0+PL);
Z= 1-(Pav/390e5);
if abs(Z-Z0)<10^-6
CF=1;
end
Z0=Z;
end
c=sqrt(Z*R*T);
k1 = (c*d)/S;
k2 = (2*f/D)*k1^2*(dx/2);
k3 = (g*sin(theta)*dx)/(2*c^2);
Q_A = block.Dwork(1).Data;
P_A = block.Dwork(2).Data;
Q_A(1:I) = Qo;
xx=0:dx:L;
if H~=0
init_press=@(x)(sqrt((P0^2-lamda*(exp(sigma*x)-1))*exp(-sigma*x)));
else
init_press=@(x)(sqrt(P0^2-phy*x));
end
for i=1:I
P_A(i)=init_press(xx(i)); %initial pressure condition
end
block.Dwork(1).Data = Q_A;
block.Dwork(2).Data = P_A;
block.Dwork(5).Data = k1;
block.Dwork(6).Data = k2;
block.Dwork(7).Data = k3;
function Outputs(block)
k1 = block.Dwork(5).Data; k2 = block.Dwork(6).Data; k3 = block.Dwork(7).Data;
Q_A = block.Dwork(1).Data;
P_A = block.Dwork(2).Data;
Q_B = block.Dwork(3).Data;
P_B = block.Dwork(4).Data;
P_in = block.InputPort(2).Data;
Q_dem = block.InputPort(1).Data;
i=1; % calculate layer B values
for i1=1:I-1
d1=(1+0.5*k3)*P_A(i+1) - k1*Q_A(i+1) + (0.5*k2)*(Q_A(i+1)^2/P_A(i+1));
d2=(0.5*k3-1)*P_A(i) - k1*Q_A(i) + (0.5*k2)*(Q_A(i)^2/P_A(i));
P_B(i1)=0.5*(d1-d2);
a=0.5*k2; b=k1*P_B(i1);
c=d2*P_B(i1) + (1+0.5*k3)*P_B(i1)^2;
Q_B(i1)= (-b + sqrt(b^2 - 4*a*c))/(2*a);
i=i+1;
end
% produce current layer A values using Layer B values
a=0.5*k2; b=k1*P_in;
d1=(1+0.5*k3)*P_B(1) - k1*Q_B(1) + (0.5*k2)*(Q_B(1)^2/P_B(1));
c=d1*P_in + (0.5*k3-1)*P_in^2;
Q_A(1)= (-b + sqrt(b^2 - 4*a*c))/(2*a); % Output 1
i1=1;
for i=2:I-1
d1=(1+0.5*k3)*P_B(i1+1) - k1*Q_B(i1+1) + (0.5*k2)*(Q_B(i1+1)^2/P_B(i1+1));
d2=(0.5*k3-1)*P_B(i1) - k1*Q_B(i1) + (0.5*k2)*(Q_B(i1)^2/P_B(i1));
P_A(i)=0.5*(d1-d2);
a=0.5*k2; b=k1*P_A(i);
c=d2*P_A(i) + (1+0.5*k3)*P_A(i)^2;
Q_A(i)= (-b + sqrt(b^2 - 4*a*c))/(2*a);
i1=i1+1;
end
a=0.5*k3+1;
d2=(0.5*k3-1)*P_B(I-1) - k1*Q_B(I-1) + (0.5*k2)*(Q_B(I-1)^2/P_B(I-1));
b=k1*Q_dem + d2;
c=0.5*k2*Q_dem^2; % Q_dem - current input
P_A(I) = (-b + sqrt(b^2 - 4*a*c))/(2*a); % Output 2
block.Dwork(1).Data = Q_A;
block.Dwork(2).Data = P_A;
block.Dwork(3).Data = Q_B;
block.Dwork(4).Data = P_B;
block.OutputPort(1).Data = Q_A(1);
block.OutputPort(2).Data = P_A(I);
%endfunction
  2 Comments
roro6992
roro6992 on 14 Jun 2014
Please tell me if there is any wrong in my s function especially in the initializeconditions method. Thank you
Geoff Hayes
Geoff Hayes on 14 Jun 2014
I don't have simulink so can't run the above, but if the code is getting stuck while intializing you may want to look at your InitializeConditions function. I noticed that there is a while loop within it - perhaps the code is getting stuck here.
Can you add some fprintfs to write out values for Z,*Z0*, and CF at each iteration?

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