如何在Matlab中创建一个“闭包函数”，如在python和js？ [英] How to create an 'closure function' in Matlab as in python and js?

问题描述

背景

在Python和JS中，我们有闭包，它返回一个带有一些预定义变量的函数。例如

  def make_printer（msg）：
 def printer（）：
 print msg 
返回打印机
  

我们在Matlab中有类似的东西吗？

这里我有一个回调函数

  function show（object，eventdata）
 
 
 code> func = @show; 
 set（gcf，'WindowButtonMotionFcn'，func）;但是，我想为这个 show   
 
 
 < c $ c>函数。 
 
 
 
目前我使用的是全局变量。 
 
 
 
关于匿名函数
 
 
 
是的我们确实在Matlab中有匿名函数。但是在我看来，支持60行程序太简单了。
解决方案
 ，我将解释我对struct的意思。我认为你调用回调函数的方式略有不同，所以这可能不太好工作）。
 
 
 
如果你有一堆不同的回调函数，你想传递给他们的一堆变量，这是恼人，很难有一个大列表的输入参数为每个函数。相反，我做这样的事情：
 
 
 
首先创建一组UI组件，但不要指定他们的回调函数，例如
  radio1_handle = uicontrol（panel1_handle，'Style'，'radiobutton'，... 
'Min'，0，'Max'，1，'Value '，0，'Units'，'normalized'，'Position'，[。8 .8 .2 .25]）; 
  
一旦你完成了所有的组件，创建一个你将使用的变量的结构
  vars = struct（'varName1'，var1，'varName2'，var2） 
  
然后更新UI组件以包含回调函数
  set（radio1_handle，'Callback'，{@ radio1_callback，vars}）; 
  
现在创建实际功能
  function radio1_callback（object，eventData，vars）
  
 ，只是一种比使用多个参数更简单的方法。
 
Background

In Python and JS we have closures, which returns a function with some of the variables pre-defined. e.g.
def make_printer(msg):
    def printer():
        print msg
    return printer


Do we have similar stuff in Matlab?

Here I have a callback function
function show(object, eventdata)
that is to be set to the callback of my GUI
func = @show;
set(gcf, 'WindowButtonMotionFcn', func);
However, I want to add some additional parameters to this show function. 

Currently I'm using global variables to do that. But I think it would be elegant if we have a 'closures function'.

About anonymous function

Yes we do have anonymous function in Matlab. However it seems to me that it is too simple to support 60-line procedures.
解决方案
Since it looks like my comment was helpful, I'll explain what I mean about the struct thing. I think the way you are calling the callback functions is slightly different, so this may not work so well).

If you have a bunch of different callback functions, and a bunch of variables you want to pass to them, it is annoying and difficult to have a big list of input arguments for each function. Instead, I do something like this:

First create a bunch of UI components , but don't specify their callback functions, e.g
radio1_handle=uicontrol(panel1_handle,'Style','radiobutton',...
    'Min',0,'Max',1,'Value',0,'Units','normalized','Position',[.8 .8 .2 .25]);
once you have made all the components, create a struct of variables you will be using
vars=struct('varName1',var1,'varName2',var2);
then update the UI components to include the callback functions
set(radio1_handle,'Callback',{@radio1_callback,vars});
now create the actual functions
function radio1_callback(object,eventData,vars)
So it's nothing fancy, just a potentially neater way than using multiple arguments.

                        
这篇关于如何在Matlab中创建一个“闭包函数”，如在python和js？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！