blocks|key|1702512|text|要正确地回答这个问题，需要更多关于问题域的信息。最有可能的是，2D数组是错误的数据结构，但是如果没有更多的信息，很难判断。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1702513|这些数组中存储的数据是什么？|1702514|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

A proper answer for this would require more information about the problem domain. Most likely, 2D arrays are the wrong data structure for this but it's hard to tell without more info.

What's the data stored in these arrays?

blocks|key|879892|text|由于您目前正在将这些保存为字符串值，最简单和最快的减小大小的方法是将它们保存为二进制值(或base64编码的字符串)。然后，您可以将所有int值转换为2个字节集(因为无符号的2个字节可以存储65536字节)，并以这种方式保存这些值。这将从每个int值5个字节降到每个int值2个字节。立即节省60%25。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|879893|对于Base64编码，我使用了我在互联网上发现的东西，叫做NSData%2BBase64。但我刚查到：|879894|In+the+iOS+7+and+Mac+OS+10.9+SDKs,+Apple+introduced+new+base64+methods+on+NSData+that+make+it+unnecessary+to+use+a+3rd+party+base+64+decoding+library.+What's+more,+they+exposed+access+to+private+base64+methods+that+are+retrospectively+available+back+as+far+as+IOS+4+and+Mac+OS+6.|offset|length|style|CODE|879895|链接。|879896|通过认识到从一个元素到另一个元素的数据很可能不会在整个范围内发生变化，你可以进一步深入到压缩过程中，因为热图总是梯度的。然后，您可以将数组保存为上次元素后的差异，并可能将其降到单个字节(255值)更改集。但如果你看到的东西温度梯度非常快(或使用低分辨率相机)，这可能会失去精确性。|879897|如果您最终需要进行压缩，我将使用GTMNSData%2Bzlib并在c#+get服务中解压缩它。因此，只要做一点点工作，它就会跨平台。|879898|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/nicklockwood/Base64|1|https://github.com/google/google-toolbox-for-mac/blob/master/Foundation/GTMNSData%252Bzlib.m^0|0|0|0|7R|0|0|3|0|0|0|G|E|G|E|1|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|10|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|11|8|@$F|12|G|13|H|I]]|9|@]|A|$]]|$1|J|3|K|5|6|7|14|8|@]|9|@$F|15|G|16|1|17]]|A|$]]|$1|L|3|M|5|6|7|18|8|@]|9|@]|A|$]]|$1|N|3|O|5|6|7|19|8|@$F|1A|G|1B|H|I]]|9|@$F|1C|G|1D|1|1E]]|A|$]]|$1|P|3|-4|5|6|7|1F|8|@]|9|@]|A|$]]]|Q|$R|$5|S|T|U|A|$V|W]]|X|$5|S|T|U|A|$V|Y]]]]

Since you are currently saving those as string values, the simplest and fastest size reduction would be to save them as binary values (or base64 encoded strings). Then you could convert all of your int values into 2 byte sets (since unsigned 2 bytes can store up to 65536) and save the values that way. That would go from 5 bytes per int value down to 2 bytes per int value. Immediate savings of 60%.

For the Base64 encoding I use something I found on the internet called NSData+Base64. But in looking that up I just read:

<code>In the iOS 7 and Mac OS 10.9 SDKs, Apple introduced new base64 methods on NSData that make it unnecessary to use a 3rd party base 64 decoding library. What's more, they exposed access to private base64 methods that are retrospectively available back as far as IOS 4 and Mac OS 6.</code>

<a href="https://github.com/nicklockwood/Base64" rel="nofollow">Link.</a>

You could go much further into the compression by realizing that data from one element to the next will likely not change by the entire range, since heat maps will always be gradients. Then you could save the arrays as difference since the last element and likely get that down to a single byte (255 value) change set. But that may lose precision if you are viewing something with a very fast heat gradient (or using a low resolution camera).

If you eventually need to get into compression, I use <a href="https://github.com/google/google-toolbox-for-mac/blob/master/Foundation/GTMNSData%2Bzlib.m" rel="nofollow"><code>GTMNSData+zlib</code></a> and decompress it in a c# webservice. So with a little bit of work it is cross platform.

blocks|key|878132|text|从去年开始，苹果就有了一个压缩库：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|878133|https://developer.apple.com/library/ios/documentation/Performance/Reference/Compression/index.html|offset|length|878134|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|2Q|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@$D|O|E|P|1|Q]]|A|$]]|$1|F|3|-4|5|6|7|R|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|C]]]]

Apple has had a compression library since last year:

<a href="https://developer.apple.com/library/ios/documentation/Performance/Reference/Compression/index.html" rel="nofollow">https://developer.apple.com/library/ios/documentation/Performance/Reference/Compression/index.html</a>

I am currently using Swift to store some data on iOS. The values come as a 2-D integer array, defined as an <code>[[Int]]</code>. I need to save these integer arrays to disk. Currently, I am using the following function to do so:

<pre><code>func writeDataToFile(data: [[Int]], filename: String){

 let fullfile = NSString(string: self.folderpath).stringByAppendingPathComponent(filename+".txt")
 var fh = NSFileHandle(forWritingAtPath: fullfile)
 if fh == nil{
 NSFileManager.defaultManager().createFileAtPath(fullfile, contents: nil, attributes: nil)
 fh = NSFileHandle(forWritingAtPath: fullfile)

 }
 fh?.writeData("Time: \(filename)\n".dataUsingEncoding(NSUTF16StringEncoding)!)
 fh?.writeData("\(data)".dataUsingEncoding(NSUTF16StringEncoding)!)
 fh?.closeFile()
}
</code></pre>

Currently this function works just fine, but it produces files that are relatively large (1.1mb each - which when you are writing them at 1 Hz, gets huge fast). The arrays written have a fixed size and the values will be from 20000 &lt; x &lt; 35000. Is there a way to compress this data on the fly such that I can later read the data into say Python or some other language? Would it just be easier to use some library like Zip to compress the files into zips after writing? Is there some way to transform the data (without loss of data/fidelity) into an image (for compression purposes, not viewing purposes). There is some metadata that I would like to store along with the 2-D array, such as a timestamp.

Compression of 2-D array on the fly with iOS

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我目前正在使用Swift在iOS上存储一些数据。这些值是一个二维整数数组，定义为[[Int]].我需要将这些整数数组保存到磁盘中。目前，我正在使用以下功能来做到这一点：func writeDataToFile(data: [[Int]], filename: String){    let fullfile = NSS...

问二维阵列的iOS动态压缩
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