✅作者简介:热爱科研的Matlab仿真开发者,修心和技术同步精进,matlab项目合作可私信。
🍎个人主页:Matlab科研工作室
🍊个人信条:格物致知。
更多Matlab完整代码及仿真定制内容点击👇
🔥 内容介绍
在机器学习领域中,支持向量机(Support Vector Machine,SVM)是一种常用的监督学习方法,它在分类和回归问题中都取得了很好的效果。然而,传统的SVM算法在处理大规模数据时会面临一些挑战,例如计算复杂度高、内存消耗大等问题。为了解决这些问题,研究人员提出了一种基于最小二乘支持向量机(Least Squares Support Vector Machine,LSSVM)的回归预测方法。
LSSVM回归预测方法通过将回归问题转化为一个最小化目标函数的优化问题,通过求解这个优化问题得到回归模型。在LSSVM中,通过引入松弛变量和惩罚项来控制模型的复杂度和泛化能力。然而,传统的LSSVM算法在求解优化问题时也存在一些问题,例如对于大规模数据的处理效率较低。为了解决这个问题,我们可以通过引入龙格库塔算法对LSSVM进行优化。
龙格库塔算法是一种常用的数值求解微分方程的方法,它通过迭代逼近来求解方程的数值解。在LSSVM中,我们可以将龙格库塔算法应用于优化问题的求解过程中,通过迭代逼近来求解最优解。这种方法可以大大提高LSSVM算法的求解效率,尤其是在处理大规模数据时。
为了实现基于龙格库塔算法优化的LSSVM回归预测方法,我们可以使用RUN-lssvm工具包。RUN-lssvm是一个开源的Python工具包,提供了一系列实现LSSVM的函数和工具,包括数据预处理、模型训练和预测等功能。使用RUN-lssvm可以方便
openai stop response
📣 部分代码
function [model,Yt] = prelssvm(model,Xt,Yt)% Preprocessing of the LS-SVM%% These functions should only be called by trainlssvm or by% simlssvm. At first the preprocessing assigns a label to each in-% and output component (c for continuous, a for categorical or b% for binary variables). According to this label each dimension is rescaled:% % * continuous: zero mean and unit variance% * categorical: no preprocessing% * binary: labels -1 and +1% % Full syntax (only using the object oriented interface):% % >> model = prelssvm(model)% >> Xp = prelssvm(model, Xt)% >> [empty, Yp] = prelssvm(model, [], Yt)% >> [Xp, Yp] = prelssvm(model, Xt, Yt)% % Outputs % model : Preprocessed object oriented representation of the LS-SVM model% Xp : Nt x d matrix with the preprocessed inputs of the test data% Yp : Nt x d matrix with the preprocessed outputs of the test data% Inputs % model : Object oriented representation of the LS-SVM model% Xt : Nt x d matrix with the inputs of the test data to preprocess% Yt : Nt x d matrix with the outputs of the test data to preprocess% % % See also:% postlssvm, trainlssvm% Copyright (c) 2011, KULeuven-ESAT-SCD, License & help @ http://www.esat.kuleuven.be/sista/lssvmlabif model.preprocess(1)~='p', % no 'preprocessing if nargin>=2, model = Xt; end returnend% % what to do% if model.preprocess(1)=='p', eval('if model.prestatus(1)==''c'',model.prestatus=''unschemed'';end','model.prestatus=''unschemed'';');end if nargin==1, % only model rescaling % % if UNSCHEMED, redefine a rescaling % if model.prestatus(1)=='u',% 'unschemed' ffx =[]; for i=1:model.x_dim, eval('ffx = [ffx model.pre_xscheme(i)];',... 'ffx = [ffx signal_type(model.xtrain(:,i),inf)];'); end model.pre_xscheme = ffx; ff = []; for i=1:model.y_dim, eval('ff = [ff model.pre_yscheme(i)];',... 'ff = [ff signal_type(model.ytrain(:,i),model.type)];'); end model.pre_yscheme = ff; model.prestatus='schemed'; end % % execute rescaling as defined if not yet CODED % if model.prestatus(1)=='s',% 'schemed' model=premodel(model); model.prestatus = 'ok'; end % % rescaling of the to simulate inputs %elseif model.preprocess(1)=='p' if model.prestatus(1)=='o',%'ok' eval('Yt;','Yt=[];'); [model,Yt] = premodel(model,Xt,Yt); else warning('model rescaling inconsistent..redo ''model=prelssvm(model);''..'); endendfunction [type,ss] = signal_type(signal,type)%% determine the type of the signal,% binary classifier ('b'), categorical classifier ('a'), or continuous% signal ('c')%%ss = sort(signal);dif = sum(ss(2:end)~=ss(1:end-1))+1;% binaryif dif==2, type = 'b';% categoricalelseif dif<sqrt(length(signal)) || type(1)== 'c', type='a';% continuelse type ='c';end %% effective rescaling%function [model,Yt] = premodel(model,Xt,Yt)%%%if nargin==1, for i=1:model.x_dim, % CONTINUOUS VARIABLE: if model.pre_xscheme(i)=='c', model.pre_xmean(i)=mean(model.xtrain(:,i)); model.pre_xstd(i) = std(model.xtrain(:,i)); model.xtrain(:,i) = pre_zmuv(model.xtrain(:,i),model.pre_xmean(i),model.pre_xstd(i)); % CATEGORICAL VARIBALE: elseif model.pre_xscheme(i)=='a', model.pre_xmean(i)= 0; model.pre_xstd(i) = 0; model.xtrain(:,i) = pre_cat(model.xtrain(:,i),model.pre_xmean(i),model.pre_xstd(i)); % BINARY VARIBALE: elseif model.pre_xscheme(i)=='b', model.pre_xmean(i) = min(model.xtrain(:,i)); model.pre_xstd(i) = max(model.xtrain(:,i)); model.xtrain(:,i) = pre_bin(model.xtrain(:,i),model.pre_xmean(i),model.pre_xstd(i)); end end for i=1:model.y_dim, % CONTINUOUS VARIABLE: if model.pre_yscheme(i)=='c', model.pre_ymean(i)=mean(model.ytrain(:,i),1); model.pre_ystd(i) = std(model.ytrain(:,i),1); model.ytrain(:,i) = pre_zmuv(model.ytrain(:,i),model.pre_ymean(i),model.pre_ystd(i)); % CATEGORICAL VARIBALE: elseif model.pre_yscheme(i)=='a', model.pre_ymean(i)=0; model.pre_ystd(i) =0; model.ytrain(:,i) = pre_cat(model.ytrain(:,i),model.pre_ymean(i),model.pre_ystd(i)); % BINARY VARIBALE: elseif model.pre_yscheme(i)=='b', model.pre_ymean(i) = min(model.ytrain(:,i)); model.pre_ystd(i) = max(model.ytrain(:,i)); model.ytrain(:,i) = pre_bin(model.ytrain(:,i),model.pre_ymean(i),model.pre_ystd(i)); end endelse %if nargin>1, % testdata Xt, if ~isempty(Xt), if size(Xt,2)~=model.x_dim, warning('dimensions of Xt not compatible with dimensions of support vectors...');end for i=1:model.x_dim, % CONTINUOUS VARIABLE: if model.pre_xscheme(i)=='c', Xt(:,i) = pre_zmuv(Xt(:,i),model.pre_xmean(i),model.pre_xstd(i)); % CATEGORICAL VARIBALE: elseif model.pre_xscheme(i)=='a', Xt(:,i) = pre_cat(Xt(:,i),model.pre_xmean(i),model.pre_xstd(i)); % BINARY VARIBALE: elseif model.pre_xscheme(i)=='b', Xt(:,i) = pre_bin(Xt(:,i),model.pre_xmean(i),model.pre_xstd(i)); end end end if nargin>2 & ~isempty(Yt), if size(Yt,2)~=model.y_dim, warning('dimensions of Yt not compatible with dimensions of training output...');end for i=1:model.y_dim, % CONTINUOUS VARIABLE: if model.pre_yscheme(i)=='c', Yt(:,i) = pre_zmuv(Yt(:,i),model.pre_ymean(i), model.pre_ystd(i)); % CATEGORICAL VARIBALE: elseif model.pre_yscheme(i)=='a', Yt(:,i) = pre_cat(Yt(:,i),model.pre_ymean(i),model.pre_ystd(i)); % BINARY VARIBALE: elseif model.pre_yscheme(i)=='b', Yt(:,i) = pre_bin(Yt(:,i),model.pre_ymean(i),model.pre_ystd(i)); end end end % assign output model=Xt;endfunction X = pre_zmuv(X,mean,var)%% preprocessing a continuous signal; rescaling to zero mean and unit% variance % 'c'%X = (X-mean)./var;function X = pre_cat(X,mean,range)%% preprocessing a categorical signal;% 'a'%X=X;function X = pre_bin(X,min,max)%% preprocessing a binary signal;% 'b'%if ~sum(isnan(X)) >= 1 %--> OneVsOne encoding n = (X==min); p = not(n); X=-1.*(n)+p;end
⛳️ 运行结果
🔗 参考文献
[1] 孙峰超.基于最小二乘支持向量机的非线性预测控制[D].中国石油大学[2023-09-28].DOI:10.7666/d.y1709445.
[2] 杨钊,路超凡,刘安黎.基于PSO-LSSVM算法的表面粗糙度预测模型与应用[J].机床与液压, 2021, 49(6):5.
[3] 刘云,易松.基于双参数最小二乘支持向量机(TPA-LSSVM)的风电时间序列预测模型的优化研究[J].北京化工大学学报:自然科学版, 2019, 46(2):6.DOI:CNKI:SUN:BJHY.0.2019-02-015.
[4] 殷樾.基于粒子群算法最小二乘支持向量机的日前光伏功率预测[J].分布式能源, 2021, 6(2):7.DOI:10.16513/j.2096-2185.DE.2106019.