array

以下代码来源于本博文作者观看 大神视频 并纯手敲。 目录 numpy的属性 创建array numpy的运算1 随机数生成以及矩阵的运算2 numpy的索引 array合并 array分割 numpy的浅拷贝和深拷贝 numpy的属性 import numpy as np array = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]) print(array) print(array.ndim) # 维度 2 print(array.shape) # 形状 (3, 3) print(array.size) # 大小 9 print(array.dtype) # 元素类型 int32 numpy创建array import numpy as np a = np.array([1, 2, 3], dtype=np.int32) print(a.dtype) # int32 b = np.array([1, 2, 3], dtype=np.float) print(b.dtype) # float64 c = np.array([1, 2, 3]) d = np.array([[1, 2, 3], [4, 5, 6]]) print(d) # 二维矩阵 zero = np.zeros((2, 3)) print(zero) #

* 在IOS开发过程中，排序是我们经常遇到的问题，那么如何进行排序呢？ * 在英文状态下，系统中有直接可以调用的方法。 例如：对数组[sss, aaa, bbb, ppp]进行排序，我们可以直接使用系统方法。 NSMutableArray * array = [[NSMutableArray alloc]initWithObjects:@"sss",@"aaa",@"bbb",@"ppp",nil]; array = (NSMutableArray *)[array sortedArrayUsingSelector:@selector(compare:)]; NSLog(@"%@",array); 上面代码的运行结果为：aaa, bbb, ppp, sss * 但是如果上面的数组中出现汉语字符，排序就会出现问题，那么在汉语数组中如何进行排序呢？ 在汉字字符串排序，因为编码问题，不能直接对汉字字符串进行直接排序。 想要对汉字进行排序，我们需要做一下准备。 1.将汉字转化成相应的拼音。 2.根据拼音将汉字排序。 一：汉字转化成相应的拼音：（例如："编码改变世界"要转化成“bianmagaibianshijie”） 将汉语转化成拼音，有很多方法，有第三方库实现，也有系统自带的方法实现。 第三方转化的比较常用的是由George编写的，使用起来比较方便

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: So I've built my program but I'm getting errors saying the same stuff over and over: benchmark.f90(17): error #6451: A dummy argument name is required in this context. [N] INTEGER, intent (in) :: N ------------------------^ benchmark.f90(18): error #6420: This array name is invalid in this context. [A] REAL, intent (out), DIMENSION (N), allocatable :: a --------------------------------------------------^ benchmark.f90(18): error #6646: ALLOCATABLE or POINTER attribute dictates a deferred-shape-array [A] REAL, intent (out), DIMENSION (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 the following JSON structure that represents an item { Id: "a", Array1: [{ Id: "b", Array2: [{ Id: "c", Array3: [ {...} ] }] }] } I need to be able to either replace the array element in Array2 with a new item or to replace just Array3 with a new array. Here is my code to replace the array item in Array2 : await Collection.UpdateOneAsync( item => item.Id.Equals("a") && item.Array1.Any(a => a.Id.Equals("b")) && item.Array1[-1].Array2.Any(b => b.Id.Equals("c")), Builders<Item>.Update.Set(s => s.Array1[-1].Array2[-1], newArray2Item) );

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 using Spark 2.1.1 and Scala 2.11.8. I have to read data from a csv file with columns ranging from minimum 6 to maximum of 8. I have to split the 9 entries and once split, columns 0 to 5 will always have data. However data can either be present or absent in columns 6 to 8. I separated and stored the required columns in a RDD using: val read_file = sc.textFile("Path to input file"); val uid = read_file.map(line => {var arr = line.split(","); (arr(2).split(":")(0),arr(3),arr(4).split(":")(0),arr(5).split(":")(0),arr(6).split(":")(0),arr(7)

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 function that takes a pointer to a floating point array. Based on other conditions, I know that pointer is actually pointing to a 2x2 OR 3x3 matrix. (in fact the memory was initially allocated as such, e.g. float M[2][2] ) The important thing is I want to make this determination in the function body, not as the function argument. void calcMatrix( int face, float * matrixReturnAsArray ) { // Here, I would much rather work in natural matrix notation if( is2x2 ) { // ### cast matrixReturnAsArray to somethingAsMatrix[2][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: Is there a convenient way to use the ARRAY_CONTAINS function in hive to search for multiple entries in an array column rather than just one? So rather than: WHERE ARRAY_CONTAINS(array, val1) OR ARRAY_CONTAINS(array, val2) I would like to write: WHERE ARRAY_CONTAINS(array, val1, val2) The full problem is that I need to read val1 and val2 dynamically from the command line arguments when I run the script and I generally don't know how many values will be conditioned on. So you can think of vals being a comma separated list (or array) containing

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: In the official Struts2 documentation I find the following snippet of code: <s:iterator value="{1,2,3,4,5}" begin="2" end="4" > <!-- current iteration value (2,3,4) --> <s:property value="top" /> </s:iterator> This iterates over the values 1 to 5. From that example, I thought any string between {} brackets would be considered as an array. I have a variable in Struts2 set to contain a string value similar to the one above, but the iterator always sees it as 1 element rather than an array of elements. None of the examples below work as

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: I have a list of several large hdf5 files, each with a 4D dataset. I would like to obtain a concatenation of them on the first axis, as in, an array-like object that would be used as if all datasets were concatenated. My final intent is to sequentially read chunks of the data along the same axis (e.g. [0:100,:,:,:] , [100:200,:,:,:] , ...), multiple times. Datasets in h5py share a significant part of the numpy array API, which allows me to call numpy.concatenate to get the job done: files = [ h5 . File ( name , 'r' ) for name in

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 does .NET not provide a class for a List<KeyValuePair<T, U>> ? I think there are a lot of situations when you need to keep an array of pairs. For example, 1 ; 2 "a" ; "array" 5 ; 8 "b" ; "browser" 1 ; 9 "f" ; "Firefox" 8 ; 10 "f" ; "frequency" Pairs < int , int > myPairs ; myPairs . Add ( 10 , 8 ); myPairs . Add ( 5 , 8 ); myPairs . Add ( 10 , 5 ); myPairs . Add ( 1 , 4 ); myPairs [ 0 ]. Value1 = 5 ; myPairs [ 5 ]. Value2 = 8 ; 回答1: This seems completely unnecessary to me - and just because you have a pair of values doesn't