如何处理在MATLAB中的函数参数名称/值对 [英] How to deal with name/value pairs of function arguments in MATLAB

问题描述

我有一个函数，可选参数的名称/值对。

I have a function that takes optional arguments as name/value pairs.

function example(varargin)
% Lots of set up stuff
vargs = varargin;
nargs = length(vargs);
names = vargs(1:2:nargs);
values = vargs(2:2:nargs);

validnames = {'foo', 'bar', 'baz'};    
for name = names
   validatestring(name{:}, validnames);
end

% Do something ...
foo = strmatch('foo', names);
disp(values(foo))
end

example('foo', 1:10, 'bar', 'qwerty')

似乎有涉及提取相应的值了很大的功夫（和它仍然不是特别强大的再厉害指定输入）。是否有处理这些名称/值对更好的办法？是否有任何辅助函数来与MATLAB帮助？

It seems that there is a lot of effort involved in extracting the appropriate values (and it still isn't particularly robust again badly specified inputs). Is there a better way of handling these name/value pairs? Are there any helper functions that come with MATLAB to assist?

推荐答案

我使用结构为我的选择是preFER。这给你一个简单的方法来存储场所和一个简单的方法来定义它们。此外，整个事情就变得相当紧凑。

I prefer using structures for my options. This gives you an easy way to store the options and an easy way to define them. Also, the whole thing becomes rather compact.

function example(varargin)

%# define defaults at the beginning of the code so that you do not need to
%# scroll way down in case you want to change something or if the help is
%# incomplete
options = struct('firstparameter',1,'secondparameter',magic(3));

%# read the acceptable names
optionNames = fieldnames(options);

%# count arguments
nArgs = length(varargin);
if round(nArgs/2)~=nArgs/2
   error('EXAMPLE needs propertyName/propertyValue pairs')
end

for pair = reshape(varargin,2,[]) %# pair is {propName;propValue}
   inpName = lower(pair{1}); %# make case insensitive

   if any(strcmp(inpName,optionNames))
      %# overwrite options. If you want you can test for the right class here
      %# Also, if you find out that there is an option you keep getting wrong,
      %# you can use "if strcmp(inpName,'problemOption'),testMore,end"-statements
      options.(inpName) = pair{2};
   else
      error('%s is not a recognized parameter name',inpName)
   end
end

这篇关于如何处理在MATLAB中的函数参数名称/值对的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！