FZERO变量非线性零发现。X = FZERO(有趣,X0)试图找到一个函数的0 X0附近的乐趣,如果X0是一个标量。它首先找到一个区间包含X0区间端点的函数值不同的符号,然后搜索时间间隔为零。有趣的是一个函数处理。有趣的接受真正的标量输入X和返回一个真正的标量函数值F,评估在X FZERO返回的值X是附近一个有趣的变化标志(如果有趣的是连续的),或南如果搜索失败。X = FZERO(有趣,X0), X0是一个向量的长度2,假定X0是一个有限区间,有趣的符号(X0(1))不同于有趣的符号(X0 (2))。如果这不是真的发生错误。调用FZERO有限区间担保FZERO将返回一个值附近一个地方有趣的变化的迹象。X = FZERO(有趣,X0), X0是一个标量值,使用X0作为开始猜测。FZERO寻找一个区间,其中包含一个信号包含X0的乐趣和变化。 If no such interval is found, NaN is returned. In this case, the search terminates when the search interval is expanded until an Inf, NaN, or complex value is found. Note: if the option FunValCheck is 'on', then an error will occur if an NaN or complex value is found. X = FZERO(FUN,X0,OPTIONS) solves the equation with the default optimization parameters replaced by values in the structure OPTIONS, an argument created with the OPTIMSET function. See OPTIMSET for details. Used options are Display, TolX, FunValCheck, OutputFcn, and PlotFcns. X = FZERO(PROBLEM) finds the zero of a function defined in PROBLEM. PROBLEM is a structure with the function FUN in PROBLEM.objective, the start point in PROBLEM.x0, the options structure in PROBLEM.options, and solver name 'fzero' in PROBLEM.solver. [X,FVAL]= FZERO(FUN,...) returns the value of the function described in FUN, at X. [X,FVAL,EXITFLAG] = FZERO(...) returns an EXITFLAG that describes the exit condition. Possible values of EXITFLAG and the corresponding exit conditions are 1 FZERO found a zero X. -1 Algorithm terminated by output function. -3 NaN or Inf function value encountered during search for an interval containing a sign change. -4 Complex function value encountered during search for an interval containing a sign change. -5 FZERO may have converged to a singular point. -6 FZERO can not detect a change in sign of the function. [X,FVAL,EXITFLAG,OUTPUT] = FZERO(...) returns a structure OUTPUT with the number of function evaluations in OUTPUT.funcCount, the algorithm name in OUTPUT.algorithm, the number of iterations to find an interval (if needed) in OUTPUT.intervaliterations, the number of zero-finding iterations in OUTPUT.iterations, and the exit message in OUTPUT.message. Examples FUN can be specified using @: X = fzero(@sin,3) returns pi. X = fzero(@sin,3,optimset('Display','iter')) returns pi, uses the default tolerance and displays iteration information. FUN can be an anonymous function: X = fzero(@(x) sin(3*x),2) FUN can be a parameterized function. Use an anonymous function to capture the problem-dependent parameters: myfun = @(x,c) cos(c*x); % The parameterized function. c = 2; % The parameter. X = fzero(@(x) myfun(x,c),0.1) Limitations X = fzero(@(x) abs(x)+1, 1) returns NaN since this function does not change sign anywhere on the real axis (and does not have a zero as well). X = fzero(@tan,2) returns X near 1.5708 because the discontinuity of this function near the point X gives the appearance (numerically) that the function changes sign at X. See also ROOTS, FMINBND, FUNCTION_HANDLE. Documentation for fzero doc fzero
