1 简介
由于进出口贸易额波动较大,影响因素较多,一般预测算法难以得到较为准确的预测结果。针对该问题,提出基于麻雀算法优化RVM模型的贸易预测方法。该方法首先找出影响进出口贸易的指标并通过主成分分析方法提取出指标的主因子作为模型的输入数据。以深圳进出口贸易预测为例验证该方法能够较为准确地预测进出口贸易值。



2 部分代码
%_________________________________________________________________________________% Salp Swarm Algorithm (SSA) source codes version 1.0%____________________________________________________________________________________function [FoodFitness,FoodPosition,Convergence_curve]=SSA(N,Max_iter,lb,ub,dim,fobj)if size(ub,1)==1ub=ones(dim,1)*ub;lb=ones(dim,1)*lb;endConvergence_curve = zeros(1,Max_iter);%Initialize the positions of salpsSalpPositions=initialization(N,dim,ub,lb);FoodPosition=zeros(1,dim);FoodFitness=inf;%calculate the fitness of initial salpsfor i=1:size(SalpPositions,1)SalpFitness(1,i)=fobj(SalpPositions(i,:));end[sorted_salps_fitness,sorted_indexes]=sort(SalpFitness);for newindex=1:NSorted_salps(newindex,:)=SalpPositions(sorted_indexes(newindex),:);endFoodPosition=Sorted_salps(1,:);FoodFitness=sorted_salps_fitness(1);%Main loopl=2; % start from the second iteration since the first iteration was dedicated to calculating the fitness of salpswhile l<Max_iter+1c1 = 2*exp(-(4*l/Max_iter)^2); % Eq. (3.2) in the paperfor i=1:size(SalpPositions,1)SalpPositions= SalpPositions';if i<=N/2for j=1:1:dimc2=rand();c3=rand();%%%%%%%%%%%%% % Eq. (3.1) in the paper %%%%%%%%%%%%%%if c3<0.5SalpPositions(j,i)=FoodPosition(j)+c1*((ub(j)-lb(j))*c2+lb(j));elseSalpPositions(j,i)=FoodPosition(j)-c1*((ub(j)-lb(j))*c2+lb(j));end%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%endelseif i>N/2 && i<N+1point1=SalpPositions(:,i-1);point2=SalpPositions(:,i);SalpPositions(:,i)=(point2+point1)/2; % % Eq. (3.4) in the paperendSalpPositions= SalpPositions';endfor i=1:size(SalpPositions,1)Tp=SalpPositions(i,:)>ub';Tm=SalpPositions(i,:)<lb';SalpPositions(i,:)=(SalpPositions(i,:).*(~(Tp+Tm)))+ub'.*Tp+lb'.*Tm;SalpFitness(1,i)=fobj(SalpPositions(i,:));if SalpFitness(1,i)<FoodFitnessFoodPosition=SalpPositions(i,:);FoodFitness=SalpFitness(1,i);endendConvergence_curve(l)=FoodFitness;l = l + 1;end
3 仿真结果

4 参考文献
[1]白霜. 基于PSO优化混合RVM模型的进出口贸易预测算法[J]. 计算机与现代化, 2014.
博主简介:擅长智能优化算法、神经网络预测、信号处理、元胞自动机、图像处理、路径规划、无人机等多种领域的Matlab仿真,相关matlab代码问题可私信交流。
部分理论引用网络文献,若有侵权联系博主删除。
该博文介绍了一种利用麻雀算法优化的RVM模型来提高进出口贸易预测的准确性。首先通过主成分分析选取关键指标,然后运用优化后的模型进行预测,并以深圳进出口贸易为例验证了方法的有效性。提供的代码实现了麻雀算法的流程。
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