array

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have a NumPy array [1,2,3,4,5,6,7,8,9,10,11,12,13,14] and want to have an array structured like [[1,2,3,4], [2,3,4,5], [3,4,5,6], ..., [11,12,13,14]] . Sure this is possible by looping over the large array and adding arrays of length four to the new array, but I'm curious if there is some secret 'magic' Python method doing just this :) 回答1: The fastest way seems to be to preallocate the array, given as option 7 right at the bottom of this answer. >>> import numpy as np >>> A=np.array([1,2,3,4,5,6,7,8,9,10,11,12,13,14]) >>> A array([ 1, 2,

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: How to document Array return value (and parameters) in JSDoc when array elements can be either of the following: A type (e.g. String , Array ). An object literal. 回答1: If you're looking for how to document the type of objects in an array, you want something like this: /** * @param {String[]} aliases */ http://code.google.com/p/jsdoc-toolkit/wiki/TagParam#Parameter_Type_Information 回答2: Given a screenings parameter: screenings = [ { timestamp: 1440157537, url: 'https://stackoverflow.com/a/22787287/1269037', }, { timestamp: ..., url: ..., }, ]

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: Why the following $a = new SplFixedArray ( 5 ); $a [ 0 ] = array ( 1 , 2 , 3 ); $a [ 0 ][ 0 ] = 12345 ; // here var_dump ( $a ); produces Notice : Indirect modification of overloaded element of SplFixedArray has no effect in on line Is it a bug? How do you deal with multidimensional SplFixedArrays then? Any workarounds? 回答1: First, the problem is related to all classes which implement ArrayAccess it is not a special problem of SplFixedArray only. When you accessing elements from SplFixedArray using the [] operator it behaves not

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have an XML document similar to the following: ... ... ... I am hoping to use the System.Xml.Serialization attributes to simplify XML deserialization. The issue I have is I cannot work out how to specify that the root node contains an array. I have tried creating the following classes: [XmlRoot("scan_details")] public class ScanDetails { [XmlArray("object")] public ScanDetail[] Items { get; set; } } public class ScanDetail { [XmlAttribute("name")] public string Filename { get; set; } } However when I deserialize the XML into the

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: My program is running though 3D array, labelling 'clusters' that it finds and then doing some checks to see if any neighbouring clusters have a label higher than the current cluster. There's a second array that holds the 'proper' cluster label. If it finds that the nth adjoining cluster is labelled correctly, that element is assigned to 0, otherwise is assigns it to the correct label (for instance if the nth site has label 2, and a neighbour is labeled 3, the 3rd element of the labelArray is set to 2). I've got a good reason to do this,

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have seen this over and over, why exactly is it faster to use fast enumeration in loops rather than an NSEnumerator using nextObject: . 回答1: NSEnumerator is the old way to enumerate over collections. It involves creating an object to represent the enumeration, then calling a method on it for every single iteration. While this was perfectly serviceable for many years, it's not terribly efficient, as it involves at least one message send for every iteration of the loop. NSFastEnumeration is the more modern approach, which leverages native

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: This question already has an answer here: How to get size c++ dynamic array 3 answers Code for dynamic array by entering size and storing it into "n" variable, but I want to get the array length from a template method and not using "n". int* a = NULL; // Pointer to int, initialize to nothing. int n; // Size needed for array cin >> n; // Read in the size a = new int[n]; // Allocate n ints and save ptr in a. for (int i=0; i This code is similar, but using a dynamic array: #include #include template inline std::size_t size( T(&)[N] ) { return N

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have a scenario in which I need to insert multiple records. I have a table structure like id (it's fk from other table), key(char), value(char). The input which needs to be saved would be array of above data. example: I have some array objects like: lst = []; obj = {}; obj.id= 123; obj.key = 'somekey'; obj.value = '1234'; lst.push(obj); obj = {}; obj.id= 123; obj.key = 'somekey1'; obj.value = '12345'; lst.push(obj); In MS SQL, I would have created TVP and passed it. I don't know how to achieve in postgres. So now what I want to do is save

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I am trying to convert a json file into csv format using a php script. The code is as follows: if (empty($argv[1])) die("The json file name or URL is missed\n"); $jsonFilename = $argv[1]; $json = file_get_contents($jsonFilename); $array = json_decode($json, true); $f = fopen('output.csv', 'w'); $firstLineKeys = false; foreach ($array as $line) { if (empty($firstLineKeys)) { $firstLineKeys = array_keys($line); fputcsv($f, $firstLineKeys); $firstLineKeys = array_flip($firstLineKeys); } fputcsv($f, array_merge($firstLineKeys, $line)); } This

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm trying to create an NSData var from an array of bytes. In Obj-C I might have done this: NSData *endMarker = [[NSData alloc] initWithBytes:{ 0xFF, 0xD9 }, length: 2] I can't figure out a working equivalent in Swift. 回答1: NSData has an initializer that takes a bytes pointer: init(bytes: UnsafeMutablePointer , length: Int) . An UnsafePointer parameter can accept a variety of different things, including a simple Swift array, so you can use pretty much the same syntax as in Objective-C. When you pass the array, you need to make sure you