MATLAB邏輯運算

MATLAB 提供了兩種類型的邏輯運算符和函數：

Element-wise - 這些運算上的對應元素的邏輯陣列。
Short-circuit - 這些運算上的標量，邏輯表達式。

元素明智的邏輯運算符操作元素元素邏輯陣列。符號＆，|和〜邏輯數組運算符AND，OR，NOT。

允許短路短路邏輯運算符，邏輯運算。符號&&和| |是短路邏輯符AND和OR。

例子

創建一個腳本文件，並鍵入下麵的代碼：

a = 5;
b = 20;
   if ( a && b )
        disp('Line 1 - Condition is true');
   end
   if ( a || b )
       disp('Line 2 - Condition is true');
   end
   % lets change the value of  a and b 
   a = 0;
   b = 10;
   if ( a && b )
       disp('Line 3 - Condition is true');
   else
       disp('Line 3 - Condition is not true');
   end
   if (~(a && b))
   
      disp('Line 4 - Condition is true');
   end

當運行該文件，它會產生以下結果：

Line 1 - Condition is true
Line 2 - Condition is true
Line 3 - Condition is not true
Line 4 - Condition is true

邏輯運算功能

除了在上述的邏輯運算符，MATLAB 提供下麵的命令或函數用於同樣的目的：

函數	描述
and(A, B)	Finds logical AND of array or scalar inputs; performs a logical AND of all input arrays A, B, etc. and returns an array containing elements set to either logical 1 (true) or logical 0 (false). An element of the output array is set to 1 if all input arrays contain a nonzero element at that same array location. Otherwise, that element is set to 0.
not(A)	Finds logical NOT of array or scalar input; performs a logical NOT of input array A and returns an array containing elements set to either logical 1 (true) or logical 0 (false). An element of the output array is set to 1 if the input array contains a zero value element at that same array location. Otherwise, that element is set to 0.
or(A, B)	Finds logical OR of array or scalar inputs; performs a logical OR of all input arrays A, B, etc. and returns an array containing elements set to either logical 1 (true) or logical 0 (false). An element of the output array is set to 1 if any input arrays contain a nonzero element at that same array location. Otherwise, that element is set to 0.
xor(A, B)	Logical exclusive-OR; performs an exclusive OR operation on the corresponding elements of arrays A and B. The resulting element C(i,j,...) is logical true (1) if A(i,j,...) or B(i,j,...), but not both, is nonzero.
all(A)	Determine if all array elements of array A are nonzero or true. If A is a vector, all(A) returns logical 1 (true) if all the elements are nonzero and returns logical 0 (false) if one or more elements are zero. If A is a nonempty matrix, all(A) treats the columns of A as vectors, returning a row vector of logical 1's and 0's. If A is an empty 0-by-0 matrix, all(A) returns logical 1 (true). If A is a multidimensional array, all(A) acts along the first nonsingleton dimension and returns an array of logical values. The size of this dimension reduces to 1 while the sizes of all other dimensions remain the same.
all(A, dim)	Tests along the dimension of A specified by scalar dim.
any(A)	Determine if any array elements are nonzero; tests whether any of the elements along various dimensions of an array is a nonzero number or is logical 1 (true). The any function ignores entries that are NaN (Not a Number). If A is a vector, any(A) returns logical 1 (true) if any of the elements of A is a nonzero number or is logical 1 (true), and returns logical 0 (false) if all the elements are zero. If A is a nonempty matrix, any(A) treats the columns of A as vectors, returning a row vector of logical 1's and 0's. If A is an empty 0-by-0 matrix, any(A) returns logical 0 (false). If A is a multidimensional array, any(A) acts along the first nonsingleton dimension and returns an array of logical values. The size of this dimension reduces to 1 while the sizes of all other dimensions remain the same.
any(A,dim)	Tests along the dimension of A specified by scalar dim.
false	Logical 0 (false)
false(n)	is an n-by-n matrix of logical zeros
false(m, n)	is an m-by-n matrix of logical zeros.
false(m, n, p, ...)	is an m-by-n-by-p-by-... array of logical zeros.
false(size(A))	is an array of logical zeros that is the same size as array A.
false(...,'like',p)	is an array of logical zeros of the same data type and sparsity as the logical array p.
ind = find(X)	Find indices and values of nonzero elements; locates all nonzero elements of array X, and returns the linear indices of those elements in a vector. If X is a row vector, then the returned vector is a row vector; otherwise, it returns a column vector. If X contains no nonzero elements or is an empty array, then an empty array is returned.
ind = find(X, k) ind = find(X, k, 'first')	Returns at most the first k indices corresponding to the nonzero entries of X. k must be a positive integer, but it can be of any numeric data type.
ind = find(X, k, 'last')	returns at most the last k indices corresponding to the nonzero entries of X.
[row,col] = find(X, ...)	Returns the row and column indices of the nonzero entries in the matrix X. This syntax is especially useful when working with sparse matrices. If X is an N-dimensional array with N > 2, col contains linear indices for the columns.
[row,col,v] = find(X, ...)	Returns a column or row vector v of the nonzero entries in X, as well as row and column indices. If X is a logical expression, then v is a logical array. Output v contains the non-zero elements of the logical array obtained by evaluating the expression X.
islogical(A)	Determine if input is logical array; returns true if A is a logical array and false otherwise. It also returns true if A is an instance of a class that is derived from the logical class.
logical(A)	Convert numeric values to logical; returns an array that can be used for logical indexing or logical tests.
true	Logical 1 (true)
true(n)	is an n-by-n matrix of logical ones.
true(m, n)	is an m-by-n matrix of logical ones.
true(m, n, p, ...)	is an m-by-n-by-p-by-... array of logical ones.
true(size(A))	is an array of logical ones that is the same size as array A.
true(...,'like', p)	is an array of logical ones of the same data type and sparsity as the logical array p.