Matlab向量化编程的利器
bsxfun函数的用法
假设A是m*n维的矩阵，B是1*n维的行向量，现在希望A的每一行都加上B，则可用下面语句
bsxfun(@plus,A,B)
实际上该语句等效为
A+repmat(B,m,1)
即把B向量扩展为与A兼容的m*n维矩阵，然后再与A相加。但在bsxfun中，这个扩展的操作是内部虚拟进行的，并不实际占用内存，因此更快。
除了@plus，还有@time，@rdivide，等二元运算，具体用法参见文献2
C = bsxfun(fun,A,B) appliesthe element-by-element binary operation specified by the functionhandlefun to arrays A and B,with singleton expansion enabled.fun can be oneof the following built-in functions:
| @plus |
Plus |
| @minus |
Minus |
| @times |
Array multiply |
| @rdivide |
Right array divide |
| @ldivide |
Left array divide |
| @power |
Array power |
| @max |
Binary maximum |
| @min |
Binary minimum |
| @rem |
Remainder after division |
| @mod |
Modulus after division |
| @atan2 |
Four quadrant inverse tangent |
| @hypot |
Square root of sum of squares |
| @eq |
Equal |
| @ne |
Not equal |
| @lt |
Less than |
| @le |
Less than or equal to |
| @gt |
Greater than |
| @ge |
Greater than or equal to |
| @and |
Element-wise logical AND |
| @or |
Element-wise logical OR |
| @xor |
Logical exclusive OR |
参考文献：