gusucode.com > symbolic工具箱matlab源码程序 > symbolic/@sym/null.m
function Z = null(A) %NULL Basis for null space. % The columns of Z = NULL(A) form a basis for the null space of A. % SIZE(Z,2) is the nullity of A. % A*Z is zero. % If A has full rank, Z is empty. % % Example: % % null(sym(magic(4))) is % % -1 % -3 % 3 % 1 % % See also SYM/COLSPACE. % Copyright 1993-2011 The MathWorks, Inc. if builtin('numel',A) ~= 1, A = normalizesym(A); end if any(reshape(~isfinite(A),[],1)) error(message('symbolic:sym:InputMustNotContainNaNOrInf')); elseif all(size(formula(A)) == 1) if A == 0 Z = sym(1); else Z = sym([]); end else Zsym = mupadmex('symobj::nullspace',A.s); Z = privResolveOutput(Zsym, A); end