看不懂有关 nargin 的程序代码
John H. Mathews著的数值方法（matlab版）中第308页有个求极小值的单纯形法程序，一开始的 if nargin==5
show=0;
end
%show==1displays iterations(P and Q)
没弄明白，这是用来做什么呀？
各位大侠，能否教我一下？谢谢！
[ 本帖最后由 eight 于 2007-8-28 18:56 编辑 ] nargin, nargout
Purpose
Number of function arguments.
Synopsis
n = nargin
n = nargout
Description
In the body of a function M-file, nargin and nargout indicate how many input or output arguments, respectively, a user has supplied.
nargin returns the number of input arguments specified for a function.
nargout returns the number of output arguments specified for a function.
Examples
This example shows portions of the code for the function fplot, which has an optional number of input and output arguments:
function = fplot(fname,lims,npts,angl,subdiv)
%FPLOT Plot a function.
% FPLOT(fname,lims,npts,angl,subdiv)
% The first two input arguments are
% required; the other three have default values.
...
% = fplot(...) returns x and y instead
% of plotting them.
...
if nargin < 5, subdiv = 20; end
if nargin < 4, angl = 10; end
if nargin < 3, npts = 25; end
...
if nargout == 0
plot(x,y)
else
x0 = x;
y0 = y;
end nargin用法示例。
函数文件examp.m：
function fout=charray(a,b,c)
if nargin==1
fout=a;
elseif nargin==2
fout=a+b;
elseif nargin==3
fout=(a*b*c)/2;
end
命令文件mydemo.m：
x=;
y=;
examp(x)
examp(x,y')
examp(x,y,3) 好厉害，谢谢！:@D 简单讲,就是判断输入变量个数.------help nargin 即知．
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