multidimensional-array

问题 I have a snippet like, Assume different length of array like, length of $name1Array is 8 and length of $name2Array is 5 for($i = 0; $i < count ( $name1Array ); $i ++) { $finalArray ["something"] [] = array ( "name1" => $name1Array [$i], "name2" => $name2Array [$i] ); } The above snippet is working all fine, but when the lengths of $name1Array and $name2Array are different? I tried 2 for loops for each one like, for($i = 0; $i < count ( $name1Array ); $i ++) { $finalArray ["something"] [] =

问题 I'm attempting to both add and remove items in a multidimensional array stored in Vuex. The array is a group of categories, and each category and have a sub-category (infinity, not simply a two dimensional array). Example data set is something like this: [ { id: 123, name: 'technology', parent_id: null, children: [ id: 456, name: 'languages', parent_id: 123, children: [ { id:789, name: 'javascript', parent_id: 456 }, { id:987, name: 'php', parent_id: 456 } ] }, { id: 333, name: 'frameworks',

问题 I'm attempting to both add and remove items in a multidimensional array stored in Vuex. The array is a group of categories, and each category and have a sub-category (infinity, not simply a two dimensional array). Example data set is something like this: [ { id: 123, name: 'technology', parent_id: null, children: [ id: 456, name: 'languages', parent_id: 123, children: [ { id:789, name: 'javascript', parent_id: 456 }, { id:987, name: 'php', parent_id: 456 } ] }, { id: 333, name: 'frameworks',

问题 int[][] arrs = {{1, 100}, {11, 22}, {1, 11}, {2, 12}}; Arrays.sort(arrs, (a, b) -> (a[0] - b[0])); Above array has been sorted as {1, 100} {1, 11} {2, 12} {11, 22} I want them to be sorted by a[0]-b[0] first and if a[0]=b[0] , then sort them by a[1]-b[1] . {1, 11} {1, 100} {2, 12} {11, 22} How to do that? 回答1: Essentially what you want to do is to compare the inner arrays lexicographically (like how words are ordered in a dictionary). Arrays.compare does exactly that. Arrays.sort(arrs, Arrays

问题 int[][] arrs = {{1, 100}, {11, 22}, {1, 11}, {2, 12}}; Arrays.sort(arrs, (a, b) -> (a[0] - b[0])); Above array has been sorted as {1, 100} {1, 11} {2, 12} {11, 22} I want them to be sorted by a[0]-b[0] first and if a[0]=b[0] , then sort them by a[1]-b[1] . {1, 11} {1, 100} {2, 12} {11, 22} How to do that? 回答1: Essentially what you want to do is to compare the inner arrays lexicographically (like how words are ordered in a dictionary). Arrays.compare does exactly that. Arrays.sort(arrs, Arrays

问题 I have multiple arrays of the following kind: import numpy as np orig_arr = np.full(shape=(5,10), fill_value=1) #only an example, actual entries different Every entry in the array above is a number to a dictionary containing further information, which is stored in an array; toy_dict = {0:np.arange(13, 23, dtype=float), 1:np.arange(23, 33, dtype=float)} My task is to replace the entries in the orig_arr with the array stored in the dict (here it is the toy_dict ) My current approach is a naive

问题 I have a 3d array created with numpy, and I was wondering how I can rotate it by a custom angle, not just the rot90 function that numpy has. Can anyone help? The 3d matrix represents an image (such as a cube, or some other shape) ie 0: 1 1 1 1 1 1 1 1 1: 1 1 1 1 2: 1 1 1 1 1 1 1 1 EDIT: Moved solution to answer 回答1: Have a look at the scipy.ndimage.interpolation.rotate function. The reason this is in scipy and not in numpy is that rotating an image 90 degrees is done by just chaning the

问题 Have there been any reliable tests that clearly display the performance differences between accessing and writing to nested vectors versus C++'s built-in arrays? I've heard that using nested (multi-dimensional) vectors typically have some performance overhead as compared to accessing elements in a single array (where all elements are stored in contiguous memory), but this just all seems to be hypothetical to me. I have yet to see any tests that actually show these differences. Are they

问题 I simply want to create an array of two dimensional arrays to store coordinate points. So I want an array where each index returns a two dimensional array which I would use as x and y . Here's what I've tried: waypoints = new int[4][,] { {{0},{6, 0}}, {{1},{1, 1}}, {{2},{1, 5}}, {{3},{6, 5}} }; I realize this probably looks stupid, but I've tried looking it up on Google, and I have not gotten any good results. It gives an error: "error CS0623: Array initializers can only be used in a variable

问题 I simply want to create an array of two dimensional arrays to store coordinate points. So I want an array where each index returns a two dimensional array which I would use as x and y . Here's what I've tried: waypoints = new int[4][,] { {{0},{6, 0}}, {{1},{1, 1}}, {{2},{1, 5}}, {{3},{6, 5}} }; I realize this probably looks stupid, but I've tried looking it up on Google, and I have not gotten any good results. It gives an error: "error CS0623: Array initializers can only be used in a variable