[原创]Matlab之按位操作

在硬件语言Verilog中按位操作是相对容易的，在C语言中一样的用好逻辑符号“|”、“!”、“&”、“>>”等即可。但是在Matlab中一些类似的操作是判断或者逻辑用法，不能用在按位操作上。那么在其中就需要用到函数来进行操作了。

在此记录两种按位操作的方法：按位左右移bitshift,按位与bitand。

按位左右移bitshift

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C = bitshift(A,K) returns the value of A shifted to the left by K bits, where A is a signed or unsigned integer array. Shifting by K bits is the same as multiplication by 2^K. Negative values of K are allowed and this corresponds to shifting to the right, or dividing by 2^ABS(K) and rounding to the nearest integer towards negative infinity. If the shift causes C to overflow the number of bits in the integer class of A, then the overflowing bits are dropped.   If A is a double array, then all elements must be non-negative integers less than or equal to intmax('uint64'), and bitshift drops any bits overflowing 64 bits.

其中K为正表示向左移，K为负值表示向右移；示例如下有：

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>> bitshift(5,1)   ans =   10   >> bitshift(5,-1)   ans =   2

按位与bitand

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C = bitand(A,B) returns the bitwise AND of arguments A and B, where A and B are signed or unsigned integer arrays. If A and B are double arrays, then they must contain non-negative integer elements less than or equal to intmax('uint64').

两个简单的示例如下：

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>> bitand(5,4)   ans =   4   >> bitand(5,15)   ans =   5

其他还有一些按位操作的函数，可以参考如下。

See also
*bitor*, *bitxor*, *bitcmp*, *bitshift*, *bitset*, *bitget*, *intmax*.