Index in position 2 exceeds array bounds (must not exceed 2).

Question

sura naji 2020-7-26

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/570607-index-in-position-2-exceeds-array-bounds-must-not-exceed-2

评论： Cris LaPierre 2020-7-27

在 MATLAB Online 中打开

please can any one help me.

Why does the following function produce the error "Index in position 2 exceeds array bounds (must not exceed 2)"?

in line C=Coord(:,H(2))-Coord(:,H(1));

clear
close all
% Problem Statement
Npar = 10;
VarLow=ones(1,10)*0.1;
VarHigh =ones(1,10)*33.5;
%BBBC parameters
N=50;       %number of candidates
MaxIter=100;  %number of iterations
% initialize a random value as best value
XBest = rand(1,Npar).* (VarHigh - VarLow) + VarLow;
[FBest]=fitnessFunc(XBest);
GB=FBest;
t = cputime;
%intialize solutions and memory
X = zeros(N, Npar);
F = zeros(N, 1);
for ii = 1:N
    X(ii,:) = rand(1,Npar).* (VarHigh - VarLow) + VarLow;
    % calculate the fitness of solutions
    F(ii) = fitnessFunc(X(ii,:));
end
%Main Loop
for it=1:MaxIter
    %Find the centre of mass 
    %-----------------------
    %numerator term
    num=zeros(1,Npar);
    for ii=1:N
        for jj=1:Npar
            num(jj)=num(jj)+(X(ii,jj)/F(ii));
        end
    end
    %denominator term
    den=sum(1./F);
    %centre of mass
    Xc=num/den; 
    %generate new solutions
    %----------------------
    for ii=1:N
        %new solution from centre of mass
        for jj=1:Npar      
            New=X(ii,:);
            New(jj)=Xc(jj)+((VarHigh(jj)*rand)/it^2);
        end
        %boundary constraints
        NewP=limiter(New,VarHigh,VarLow);
        %new fitness
        newFit=fitnessFunc(New);
        %check whether the solution is better than previous solution
        if newFit<F(ii)
            X(ii,:)=New;
            F(ii)=newFit;
            if F(ii)<FBest
                XBest=X(ii,:);
               FBest=F(ii);   
            end
        end
    end
    % store the best value in each iteration
    GB=[GB FBest];
    
end
t1=cputime;
fprintf('The time taken is %3.2f seconds \n',t1-t);
fprintf('The best value is :');
XBest
FBest
figure(1)
plot(0:MaxIter,GB, 'linewidth',1.2);
title('Convergence');
xlabel('Iterations');
ylabel('Objective Function (Cost)');
grid('on')
function newP=limiter(P,VarHigh,VarLow)
newP=P;
for i=1:length(P)
    if newP(i)>VarHigh
        newP(i)=VarHigh;
    elseif newP(i)<VarLow
        newP(i)=VarLow;
    end
end
 
end
function [WE,FBest]=fitnessFunc(X)
Coord=360*[2 1;2 0;1 1;1 0;0 1;0 0]; 
Con=[5 3;1 3;6 4;4 2;3 4;1 2;6 3;5 4;4 1;3 2];
Re=[0 0;0 0;0 0;0 0;1 1;1 1 ];
Load=zeros(size(Coord));
Load(2,:)=[0 -1e5];
Load(4,:)=[0 -1e5];
E=ones(1,size(Con,1))*1e7;
A=ones(1,10);
%Allowable Stress
TM=25000;%psi
%Allowable Displacement
DM=2;%inch
%Density
RO=0.1;%lb/in^3
w=size(Re);
S=zeros(3*w(2));
U=1-Re;f=find(U);
WE=0;
for i=1:size(Con,2)
    H=Con(:,i);
    C=Coord(:,H(2))-Coord(:,H(1));      *********problem here
    Le=norm(C);
    T=C/Le;
    s=T*T';
    G=E(i)*A(i)/Le;
    Tj(:,i)=G*T;
    e=[3*H(1)-2:3*H(1),3*H(2)-2:3*H(2)];
    S(e,e)=S(e,e)+G*[s -s;-s s];
    WE=WE+Le*D.A(i)*D.RO;
end
U(f)=S(f,f)\Load(f);
F=sum(Tj.*(U(:,Con(2,:))-U(:,Con(1,:))));
R=reshape(S*U(:),w);
R(f)=0;
TS=(((abs(F'))./A)/TM)-1;%Tension
US=abs(U')/DM-1;%Displacement
PS=sum(TS.*(TS>0));
PD=sum(sum(US.*(US>0)));
FBest=WE*(1+PS+PD)^2;% Penalty function
end

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Answer 1

Cris LaPierre 2020-7-26

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/570607-index-in-position-2-exceeds-array-bounds-must-not-exceed-2#answer_470926

编辑：Cris LaPierre 2020-7-27

在 MATLAB Online 中打开

You define Coord to be a 5x2 array

Coord=360*[2 1;2 0;1 1;1 0;0 1;0 0];

Since Coord only has 2 columns, you can't ask for a column higher than 2 (the 2nd index value). However, in the line of code giving you an error (C=Coord(:,H(2))-Coord(:,H(1)), when i=1, then H(1)=5 and when i=2, then H(1)=H(2)=3.