用matlab的ezplot 和 abs 出错~

用matlab的ezplot 和 abs 出错~syms wezplot( abs( w ) ) 这个命令能画出图来但是下面这个syms wezplot( abs( exp(w) ) )这个命令不能出图求助~~~具体的错误提示如下? Error using ==> inlineeval at 15Error in inline expression ==> exp(Re(w)) Undefined function or method 'Re' for input arguments of type 'double'.Error in ==> inline.feval at 36 INLINE_OUT_ = inlineeval(INLINE_INPUTS_, INLINE_OBJ_.inputExpr, INLINE_OBJ_.expr);Error in ==> ezplotfeval at 52 z = feval(f,x(1));Error in ==> ezplot>ezplot1 at 464[y,f,loopflag] = ezplotfeval(f,x);Error in ==> ezplot at 144 [hp,cax] = ezplot1(cax,f{1},vars,labels,args{:});Error in ==> sym.ezplot at 45 h = ezplot(char(f));Error in ==> Untitled5 at 2ezplot( abs( exp(w) ) )