www.gusucode.com > elmat工具箱matlab源码程序 > elmat/find.m
%FIND Find indices of nonzero elements. % I = FIND(X) returns the linear indices corresponding to % the nonzero entries of the array X. X may be a logical expression. % Use IND2SUB(SIZE(X),I) to calculate multiple subscripts from % the linear indices I. % % I = FIND(X,K) returns at most the first K indices corresponding to % the nonzero entries of the array X. K must be a positive integer, % but can be of any numeric type. % % I = FIND(X,K,'first') is the same as I = FIND(X,K). % % I = FIND(X,K,'last') returns at most the last K indices corresponding % to the nonzero entries of the array X. % % [I,J] = FIND(X,...) returns the row and column indices instead of % linear indices into X. This syntax is especially useful when working % with sparse matrices. If X is an N-dimensional array where N > 2, then % J is a linear index over the N-1 trailing dimensions of X. % % [I,J,V] = FIND(X,...) also returns a vector V containing the values % that correspond to the row and column indices I and J. % % Example: % A = magic(3) % find(A > 5) % % finds the linear indices of the 4 entries of the matrix A that are % greater than 5. % % [rows,cols,vals] = find(speye(5)) % % finds the row and column indices and nonzero values of the 5-by-5 % sparse identity matrix. % % See also SPARSE, IND2SUB, RELOP, NONZEROS. % Copyright 1984-2005 The MathWorks, Inc. % Built-in function.