matlab 使用cvx出现Cannot perform the operation: {convex} ./ {convex}

错误：Disciplined convex programming error:
Cannot perform the operation: {convex} ./ {convex}
源代码：
maxv=max(max(B1));
B1=B1./maxv;
B1是一个矩阵，我想把他除以最大值归一化，为什么会出错呀