紧急求助：关于bp神经网络的输出向量问题

dobee

　　小弟编辑一段bp神经网络程序，运行时，系统报错提示：Targets are incorrectly sized for network.Matrix must have 1 rows.　是否bp神经网络的目标输出都只能是一维向量？如果多维可以，此程序应如何修改？请大家多指教，期待尽快回复，急！！！

pp=[p1;p2;p3;p4;p5;p6;p7;p8;p9];         ％pp为540*21矩阵
T=[1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0;
    0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0;
    0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0;
    0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0;
    0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0;
    0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0;
    0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0;
    0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0;
    0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0];
p=pp';
t=T;
% 归一化训练样本
for i=1:21
    p(:,i)=(p(:,i)-min(p(:,i)))/(max(p(:,i))-min(p(:,i)));
end


%----------------------确定隐层神经元---------------------------------------------

   net=newff(minmax(p),[11,1],{'tansig','logsig'},'traingdx');     %最速下降BP法，节省机器内存
inputWeights=net.iw{1,1};
inputbias=net.b{1,1};
layerWeights=net.iw{2,1};
layerbias=net.b{2,1};
    net.trainParam.lr = 0.05;
net.trainParam.show = 50;
net.trainParam.epochs = 10000;
net.trainParam.goal = 0.0002;
   net=train(net,p,t);
   YY=sim(net,p);