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 want to do a simple dynamic array of ints in my j2me application, The only dynamic array I see is "java.util.Vector" and this one doesn't seem to accept an int as a new element (only wants Objects). So how do I go around fixing that problem? 回答1: public class DynamicIntArray { private static final int CAPACITY_INCREMENT = 10; private static final int INITIAL_CAPACITY = 10; private final int capacityIncrement; public int length = 0; public int[] array; public DynamicIntArray(int initialCapacity, int capacityIncrement) { 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: Let's say I had a Ruby Array of Date s like: 2011-01-20 2011-01-23 2011-02-01 2011-02-15 2011-03-21 What would be an easy and Ruby-esque way of creating a Hash that groups the Date elements by year and then month, like: { 2011 => { 1 => [2011-01-20, 2011-01-23], 2 => [2011-02-01, 2011-02-15], 3 => [2011-03-21], } } I can do this by iterating over everything and extracting years, months and so on, then comining them. Ruby offers so many methods and blocks for Arrays and Hashes, there must be an easier way? 回答1: require 'date' dates = [ '2011

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 main array of tags var tagsArray = [ { name: "1", selected: undefined }, { name: "2", selected: undefined }, { name: "3", selected: undefined } ] Then an array of selected tags to compare it to: var selectedTags = [ { name: "1", selected: true } ] How would you run some kind of comparison (for-loop) to check what objects in selectedTags have the selected: true value? Then also set the same object's selected value in tagsArray to true ? 回答1: Create an access map, then iterate and find the true values and set the values in the other

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 want to set all the index value to -1 in a double array. Here is my code : double dp[505]; memset(dp,-1,sizeof(dp)); cout<<dp[0]<<"\n"; But it is showing nan when i try to print its value. What does nan mean? Is it possible to use memset() in double array? 回答1: In C++, you can write: double initValue = -1; std::fill_n(dp, 505, initValue); memsetting a double array with a non-double value won't work. 回答2: memset operates on bytes, not floats, and a double with all bytes set to -1 does not equal -1. I think you're looking for std::fill :

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 code sample private $analyze_types = array( "1" => array( 'level' => '4', 'l1' => '-1', 'l2' => '-1', 'l3' => '-1', 'l4' => '-1', 'l5' => '-1' ), "226" => array( 'level' => '-1', 'l1' => '-1', 'l2' => '-1', 'l3' => '2', 'l4' => '3', 'l5' => '4' ) ); How can i get value of "1" and if I want to get 'level' value, what should i do? 回答1: PHP : foreach( $this->analyze_types as $key => $value) { echo $key; // output 1 and 226 echo $value['level']; // output 4 and -1 } 回答2: To get element with index 'level' of subarray with

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 2D array and two masks, one for columns, and one for rows. If I try to simply do data[row_mask,col_mask] , I get an error saying shape mismatch: indexing arrays could not be broadcast together with shapes ... . On the other hand, data[row_mask][:,col_mask] works, but is not as pretty. Why does it expect indexing arrays to be of the same shape? Here's a specific example: import numpy as np data = np.array([[1,2,3],[4,5,6],[7,8,9],[10,11,12]]) row_mask = np.array([True, True, False, True]) col_mask = np.array([True, True, False])

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, you have n sorted arrays (not necessarily of equal length), and you are to return the kth smallest element in the combined array (i.e the combined array formed by merging all the n sorted arrays) I have been trying it and its other variants for quite a while now, and till now I only feel comfortable in the case where there are two arrays of equal length, both sorted and one has to return the median of these two. This has logarithmic time complexity. After this I tried to generalize it to finding kth smallest among two sorted arrays. Here

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 ValueError: 'object too deep for desired array' in a Python program. I have this error while using numpy.digitize. I think it's how I use Pandas DataFrames: To keep it simple (because this is done through an external library), I have a list in my program but the library needs a DataFrame so I do something like this: ts = range(1000) df = pandas.DataFrame(ts) res = numpy.digitize(df.values, bins) But then it seems like df.values is an array of lists instead of an array of floats. I mean: array([[ 0], [ 1], [ 2], ..., [997], [998],

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 question about a pointer to 2d array. If an array is something like int a[2][3]; then, is this a pointer to array a ? int (*p)[3] = a; If this is correct, I am wondering what does [3] mean from int(*p)[3] ? 回答1: Rather than referring to int[2][3] as a '2d array', you should consider it to be an 'array of arrays'. It is an array with two items in it, where each item is itself an array with 3 ints in it. int (*p)[3] = a; You can use p to point to either of the two items in a . p points to a three-int array--namely, the first such item

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 two pictures, one that was the original and another one that I have modified so that it's translated up and left a bit and then rotated 90 degrees (so the shape of the picture is transposed as well). Now I'd like to determine how many pixels (or any distance unit) the modified picture is translated from the original, as well as the degrees of rotation relative to the original. Phase correlation is supposed to solve this problem by first converting the coordinates to logpolar coordinates, then doing a number of things so that in the