24小时热门版块排行榜    

查看: 2803  |  回复: 0

samggyy

金虫 (小有名气)

[求助] Matlab如何使用绘图画出3D SVM的decision boundary?

RT,Matlab中可以画出二维的SVM的decision boundary,代码如下,

    load fisheriris;
   
    features = meas(1:100,;
    featureSelcted = features(1:100,1:2);
    groundTruthGroup = species(1:100);
   
   
    svmStruct = svmtrain(featureSelcted, groundTruthGroup, ...
        'Kernel_Function', 'rbf', 'boxconstraint', Inf, 'showplot', true, 'Method', 'QP');
    svmClassified = svmclassify(svmStruct,featureSelcted,'showplot',true);

如果使用三维的特征,即把代码改为featureSelcted = features(1:100,1:3); 无法出一个三维的超平面了。思路可能是:

cubeXMin = min(featureSelcted(:,1))-0.5;
cubeYMin = min(featureSelcted(:,2))-0.5;
cubeZMin = min(featureSelcted(:,3))-0.5;

cubeXMax = max(featureSelcted(:,1))+0.5;
cubeYMax = max(featureSelcted(:,2))+0.5;
cubeZMax = max(featureSelcted(:,3))+0.5;

cubeMesh = meshgrid(cubeXMin:0.5:cubeXMax,cubeYMin:0.5:cubeYMax,cubeZMin:0.5:cubeZMax);

sv = svmStruct.SupportVectors;
alphaHat = svmStruct.Alpha;
bias = svmStruct.Bias;
kfun = svmStruct.KernelFunction;
kfunargs = svmStruct.KernelFunctionArgs;

f = (feval(kfun,sv,cubeMesh,kfunargs{:})'*alphaHat() + bias;

decisionBoundary = sign(f);
decisionBoundaryInd = find(decisionBoundary==0);

figure,
scatter3(featureSelcted(:,1),featureSelcted(:,2),featureSelcted(:,3));
surf(decisionBoundaryInd);

但是不知道怎么完成,请教有没有人知道怎么做的。谢谢!


有一个用R写的例子:
http://stackoverflow.com/questio ... -svm-fit-hyperplane

还有两篇论文中也有做到:
http://www.sciencedirect.com/sci ... i/S0304394010006324
http://www.mathematica-journal.c ... ation-with-kernels/
回复此楼
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

智能机器人

Robot (super robot)

我们都爱小木虫

找到一些相关的精华帖子,希望有用哦~

科研从小木虫开始,人人为我,我为人人
相关版块跳转 我要订阅楼主 samggyy 的主题更新
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[硕博家园] 售SCI一区T0P文章,我:8.O55.1.O.54,科目全,可十急 +3 vZfe6xYu34yj 2026-09-14 3/150 2026-09-18 02:16 by cITaGg3p5edr
[硕博家园] 售SCI一区T0P文章,我:8.O.55.1.O.5.4,科目全,可+急 +4 Aj1rhIDL5ixY 2026-09-14 4/200 2026-09-18 01:54 by cITaGg3p5edr
[考博] 售SCI一区T0P文章,我:8.O.55.1.O.5.4,科目全,可+急 +3 Aj1rhIDL5ixY 2026-09-14 3/150 2026-09-18 01:40 by cITaGg3p5edr
[硕博家园] 售SCI一区T0P文章,我:8.O.55.1.O54,科目全,可伽急 +4 40ms4Wlo4umh 2026-09-14 4/200 2026-09-18 01:04 by cITaGg3p5edr
[找工作] 售SCI一区T0P文章,我:8O.55.1.O.5.4,科目齐全,可+急 +6 s3fFTmArrBt6 2026-09-13 6/300 2026-09-17 23:28 by cuPZTDXS3VOd
[硕博家园] 售一区SCI文章T0P,我:8O.551.O54,科目全,可十急 +7 LwdutQ8HoqWP 2026-09-13 7/350 2026-09-17 22:53 by cuPZTDXS3VOd
[有机交流] 各位大神,目前国内有哪些比较好用的逆合成软件? 20+3 zapen 2026-09-15 7/350 2026-09-17 16:40 by 北京莱茵编辑
[考博] 售一区SCI文章T0P,我:8O.551.O54,科目全,可十急 +4 5BDX0d0WFp7t 2026-09-15 4/200 2026-09-17 16:29 by 0ngsZVSCTS7z
[考博] 售SCI文章,我:8O.5.5.1O.54,科目全,可十急 +3 vZfe6xYu34yj 2026-09-14 3/150 2026-09-17 15:29 by 0ngsZVSCTS7z
[硕博家园] 售SCI一区T0P文章,我:8.O.55.1.O54,科目全,可伽急 +4 23jxep3nCNZb 2026-09-14 4/200 2026-09-17 13:51 by ObVzqQQh1rrE
[找工作] 售SCI一区T0P文章,我:8.O.55.1.O.54,科目齐全,可+急 +4 mibUvS8DDCwf 2026-09-15 4/200 2026-09-17 06:26 by k06BKNblrGRH
[考研] 售SCI一区文章,我:8.O.55.1.O.54,科目齐全,可伽急 +3 vZfe6xYu34yj 2026-09-14 3/150 2026-09-16 22:26 by Tql5LQhh5rLK
[考博] 售SCI-T0P文章,我:8O.5.5.1.O.54,科目齐全,可+急 +4 6F5UbRU2I5hL 2026-09-14 4/200 2026-09-16 17:00 by i3KBRD19ERkG
[考研] 售SCI一区T0P文章,我:8.O.55.1.O.5.4,科目全,可+急 +4 s3fFTmArrBt6 2026-09-13 6/300 2026-09-16 16:00 by i3KBRD19ERkG
[考研] 售SCI一区T0P文章,我:8.O.55.1.O.5.4,科目全,可+急 +5 LwdutQ8HoqWP 2026-09-13 5/250 2026-09-16 03:14 by DgNGHc3h5tPl
[考博] 售SCI一区T0P文章,我:8O.55.1.O.5.4,科目齐全,可+急 +5 3n8v2C8RimXI 2026-09-13 5/250 2026-09-16 02:50 by DgNGHc3h5tPl
[考博] 售SCI一区T0P文章,我:8.O.55.1.O.5.4,科目全,可+急 +3 6F5UbRU2I5hL 2026-09-14 3/150 2026-09-15 17:39 by CgyNCDVNhGVg
[考博] 售SCI一区文章,我:8O5.5.1.O5.4,科目全,可伽急 +7 s3fFTmArrBt6 2026-09-14 7/350 2026-09-15 16:23 by CgyNCDVNhGVg
[教师之家] 售SCI一区文章,我:8.O.551.O.5.4,科目全,可伽急 +4 s3fFTmArrBt6 2026-09-13 4/200 2026-09-15 07:02 by 5BDX0d0WFp7t
[考博] 27秋季材料博士申请求助 10+3 Cahal1 2026-09-11 4/200 2026-09-14 08:50 by 北京莱茵编辑
信息提示
请填处理意见