什么是空图形设备?

I'm reading the R help page for ?devAskNewPage (it was linked from ?par...ask). I can't understand what par(ask=F) / par(ask=T) does.

我正在为devAskNewPage阅读R帮助页面(它是从?par…ask链接过来的)。我不明白par(ask=F) / par(ask=T)做什么。

What do I need to read about to understand this:

要理解这一点，我需要读些什么:

 If the current device is the null device, this will open a
 graphics device.

 ...

 The precise circumstances when the user will be asked to confirm a
 new page depend on the graphics subsystem.  Obviously this needs
 to be an interactive session.  In addition ‘recording’ needs to be
 in operation, so only when the display list is enabled (see
 ‘dev.control’) which it usually is only on a screen device.

What are devices, what is the null device, and what is a graphics subsystem? What is 'recording'? Are we talking about the difference between writing to png file and writing to the screen?

什么是设备，什么是空设备，什么是图形子系统?“记录”是什么?我们是在讨论写png文件和写屏幕的区别吗?

This feels a bit like learning what standard output and standard input are. Everybody uses the words but it was hard to find the definition (it was also hard to understand it). I googled for "null graphics device" and the top results don't explain to me, as a novice, what I need to know, in order to know where to look.

这有点像学习什么是标准输出和标准输入。每个人都用这个词，但很难找到定义(也很难理解)。我在谷歌上搜索“空图形设备”，上面的结果并没有向我解释，作为一个新手，我需要知道什么，才能知道去哪里找。

Just some links to the proper introductory reading would suffice. Thank you.

只要一些适当的介绍性阅读的链接就足够了。谢谢你！

1 个解决方案

#1

In R, a device is the mechanism to produce graphical plots. This can be to screen (e.g. windows ) or to a variety of file types (e.g. png, pdf, tiff, etc).

在R中，设备是产生图形图的机制。这可以用于屏幕(如windows)或各种文件类型(如png、pdf、tiff等)。

For an entry point to the help file on devices, see ?Devices. The default devices for the three main operating systems are:

有关设备上的帮助文件的入口点，请参见“设备”。三个主要操作系统的默认设备是:

MS Windows: windows
Windows女士:窗户
Unix: X11
Unix:X11
OS X: quartz
OS X:石英

The null device means that no device is active. Here is a short code sequence that I used to find out whether I had an open device (dev.cur) and close it (dev.off). When I closed it, the remaining device was the null device.

空设备意味着没有激活的设备。这里是一个简短的代码序列，我用来查找是否有一个打开的设备(dev.cur)并关闭它(dev.off)。当我关闭它时，剩下的设备是空设备。

> dev.cur()
windows 
      2 

> dev.off(2)
null device 
          1 

> dev.cur()
null device 
          1

The meaning of graphics sybsystem is a bit more unclear. This seems to be the only page in all of help that uses the term. Thus I am guessing that the following are graphics subsystems:

图形系统的意义就不太清楚了。这似乎是所有帮助中使用这个术语的唯一一页。因此我猜想以下是图形子系统:

base graphics
基本图形
grid graphics (and anything built on top, including lattice and ggplot2)
网格图形(以及任何构建在上面的东西，包括晶格和ggplot2)
rgl in package rgl
在包rgl rgl

#1