输入任意正整数，返回Pascal's Matrix

你好，把我以前编写的Yanghui改成pacalMat就行

function Y = Yanghui(n)
if(n==1)
    Y = 1;
else
    Y = zeros(n);
    X = Yanghui(n-1);
    Y(n,:) = conv(X(n-1,:),[1,1]);
    Y(1:n-1,1:n-1) = X;
end
end

示例：

>> Yanghui(4)

ans =

     1     0     0     0
     1     1     0     0
     1     2     1     0
     1     3     3     1