How to fix : Unable to perform assignment because the left and right sides have a different number of elements.

2 次查看（过去 30 天）
Supreeth D K
Supreeth D K 2023-1-18
评论： Supreeth D K 2023-1-18
I am trying to use particle swarm optimization to solve a problem of mine.
And i get following error:
Unable to perform assignment because the left and right sides have a
different number of elements.
This is the initial code:
function output= fun(X)
g(:,1)=[2;2]; R1=X(:,1); R3=X(:,2); R2= R3-g; n=X(:,3);
Br1=1.2;Br2=1.2;mu=4.*pi.*10.^-7;R4=35;
Length=70; L=2.*pi.*sqrt((R4.^2+R1.^2)./2);
x=(Br1.*Br2.*L.*(10^-6))/(4.*pi.*mu);
a=Length./n;
b=R2-R1;
d=R4-R3;
h=R3-R2;
c=-10:0.5:0;
F=0;
I feel there is an issue with how i have defined the variables.
  2 个评论
Dyuman Joshi
Dyuman Joshi 2023-1-18
What is the full error and in which line does it occur?
Mention the code that is relevant to the line where the error occurs.
Supreeth D K
Supreeth D K 2023-1-18
This is the PSO code i have used and error occurs in line 152
clc;
clear;
close all;
%% Problem Definition
run=5;
for i=1:run
CostFunction = @(X)-fun(X); % maximizing Function
nVar = 3; % Number of parameter
VarSize = [1 nVar]; % Size of Decision Variables Matrix
VarMin = [10 0.5 1]; % Lower Bound of parameters
VarMax = [40 5.5 2.5]; % Upper Bound of parameters
%% PSO Parameters
MaxIt = 1000; % Maximum Number of Iterations
nPop = 50; % Population Size (Swarm Size)
% PSO Parameters
w = 1; % Inertia Weight
wdamp = 0.99; % Inertia Weight Damping Ratio
c1 = 1; % Personal Learning Coefficient
c2 = 1.5; % Global Learning Coefficient
% Velocity Limits
VelMax = 0.1*(VarMax-VarMin);
VelMin = -VelMax;
%% Initialization
empty_particle.Position = [];
empty_particle.Cost = [];
empty_particle.Velocity = [];
empty_particle.Best.Position = [];
empty_particle.Best.Cost = [];
particle = repmat(empty_particle, nPop, 1);
GlobalBest.Cost = inf;
for i = 1:nPop
% Initialize Position
particle(i).Position = unifrnd(VarMin, VarMax, VarSize);
% Initialize Velocity
particle(i).Velocity = zeros(VarSize);
% Evaluation
particle(i).Cost = CostFunction(particle(i).Position);
% Update Personal Best
particle(i).Best.Position = particle(i).Position;
particle(i).Best.Cost = particle(i).Cost;
% Update Global Best
if particle(i).Best.Cost<GlobalBest.Cost
GlobalBest = particle(i).Best;
end
end
BestCost = zeros(MaxIt, 1);
%% PSO Main Loop
for it = 1:MaxIt
for i = 1:nPop
% Update Velocity
particle(i).Velocity = w*particle(i).Velocity ...
+c1*rand(VarSize).*(particle(i).Best.Position-particle(i).Position) ...
+c2*rand(VarSize).*(GlobalBest.Position-particle(i).Position);
% Apply Velocity Limits
particle(i).Velocity = max(particle(i).Velocity, VelMin);
particle(i).Velocity = min(particle(i).Velocity, VelMax);
% Update Position
particle(i).Position = particle(i).Position + particle(i).Velocity;
% Velocity Mirror Effect
IsOutside = (particle(i).Position<VarMin | particle(i).Position>VarMax);
particle(i).Velocity(IsOutside) = -particle(i).Velocity(IsOutside);
% Apply Position Limits
particle(i).Position = max(particle(i).Position, VarMin);
particle(i).Position = min(particle(i).Position, VarMax);
% Evaluation
particle(i).Cost = CostFunction(particle(i).Position);
% Update Personal Best
if particle(i).Cost<particle(i).Best.Cost
particle(i).Best.Position = particle(i).Position;
particle(i).Best.Cost = particle(i).Cost;
% Update Global Best
if particle(i).Best.Cost<GlobalBest.Cost
GlobalBest = particle(i).Best;
end
end
end
BestCost(it) = GlobalBest.Cost;
w = w*wdamp;
end
BestSol = GlobalBest;
disp(BestSol);
end
%% Results
figure;
%plot(BestCost, 'LineWidth', 2);
semilogy(BestCost, 'LineWidth', 2);
xlabel('Iteration');
ylabel('Best Cost');
grid on;

请先登录，再进行评论。

请先登录，再回答此问题。

回答（1 个）

KSSV
KSSV 2023-1-18
Ran in:
This is a simple error, it occurs when you try to save more number of elements into an array than it is initialized for.
Ex:
A = zeros(1,3) ;
A(1) = rand ; % filling one element in one position
A(2) = rand(1,2) ; % filling two elements in one position; not correct so error
Unable to perform assignment because the left and right sides have a different number of elements.

类别

在 Help Center 和 File Exchange 中查找有关 Particle Swarm 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by