How to save the data every time i run 3 For loops?

I run a Mass-spring-damper system and i want to calculate percentage error of all combinations. Then find the value with the minimum error. But i could not save the data . It only saves the one of the last

for K1 = 170000:5000:210000
    for B1 = 0:10:100
        for M1 = 1:0.05:1.2
            sim('MSDsystem');
            Display=ans.Displacement(:,2);
            delta=abs(Display-Mass1(:,2));
            percentagediff=delta./Mass1(:,2);
            meanpctdiff=mean(percentagediff);
            mat(K1,:)=meanpctdiff
            
        end
    end
end

Answer 1

[madhan ravi]

K1 = 170000:5000:210000;
B1 = 0:10:100;
M1 = 1:0.05:1.2;
kn = numel(K1);
bn = numel(B1);
mn = numel(M1);
mat=zeros(kn,bn,mn); % preallocate
for k1 = 1:kn
    for b1 = 1:bn
        for m1 = 1:mn
            S=sim('MSDsystem');
            Display=S.Displacement(:,2);
            delta=abs(Display-Mass1(:,2));
            percentagediff=delta./Mass1(:,2);
            meanpctdiff=mean(percentagediff);
            mat(k1,b1,m1)=meanpctdiff;            
        end
    end
end

[Nikhil Murali Krishnaa]

but now the the variables inside simulink does not change. How do i do that?

[madhan ravi]

I’m not full fledged in Simulink sorry.

Answer 2

[KSSV]

for K1 = 170000:5000:210000
    for B1 = 0:10:100
        for M1 = 1:0.05:1.2
            sim('MSDsystem');
            Display=ans.Displacement(:,2);
            delta=abs(Display-Mass1(:,2));
            percentagediff=delta./Mass1(:,2);
            meanpctdiff=mean(percentagediff);
            mat(K1,B1,M1)=meanpctdiff
            
        end
    end
end

It is suggested to pre-allocate mat before loops.

[Nikhil Murali Krishnaa]

It is showing an error as "Index in position 2 is invalid. Array indices must be positive integers or logical values."

[Nikhil Murali Krishnaa]

The problem is it is taking the value K1 has the array size. But the loop runs only 495 times